“According to the United Nations Development Programme (UNDP), a shanty town is a disadvantaged part of a city characterised by very unhealthy housing built by the inhabitants from salvaged materials, extreme poverty and no rights or security of tenure. According to the World Bank, over 60% of Africa’s urban population now lives in shanty towns. These almost 285 million urban dwellers represent 60% of Africa’s urban population. In 2003, Africans living in shanty towns made up 71.9% of the urban population.”

From Afrik 21.

“Cities, the dense agglomerations that dot the globe, have been engines of innovation since Plato and Socrates bickered in an Athenian marketplace,” as urban economist Edward Glaeser explains in his book The Triumph of the City.

Athens’s storied breakthroughs in philosophy are but one example of how cities have often been the sites of pivotal advances throughout history. Kyoto gave us the novel. Bologna gave us the university. Florence gave us the Renaissance. Paris gave us the Enlightenment. Manchester gave us the Industrial Revolution. Los Angeles gave us cinema. Postwar New York gave us modern finance . . . the list goes on. As Glaeser also notes, “Wandering these cities—whether down cobblestone sidewalks or grid-cutting cross streets, around roundabouts or under freeways—is to study nothing less than human progress.”

If you’re not able to travel to each of these extraordinary cities, perhaps the next best thing is to embark on a virtual tour from the comfort of your home. To that end, I wrote a book surveying 40 of history’s greatest urban centers, showcasing each city at a moment in time when it notably contributed to progress.

Centers of Progress: 40 Cities That Changed the World offers a fact-filled yet accessible crash course in global urban history, spanning from the agricultural revolution to the digital revolution. This book affirms the importance of cities to the story of human progress and innovation by shining a spotlight on some of the places that have helped create the modern world.

The book’s chapters can guide you through the Library of Alexandria, the stock exchange of Dutch Golden Age-era Amsterdam, and the pubs of Edinburgh during the Scottish Enlightenment, all in an afternoon.

Centers of Progress “takes the reader on a time-travel cruise through the great flash points of human activity to catch innovations that have transformed human lives” at their moment of invention, according to writer Matt Ridley in the insightful foreword that he kindly provided. Come explore Agra as the Taj Mahal was erected and Cambridge as Isaac Newton penned the Principia. Meet engineers in Ancient Rome, Silk Road merchants in Tang Dynasty Chang’an, music composers in 19th-century Vienna, and Space Age flight controllers in Houston.

Learning about past achievements may even hold the secret to fostering innovation in the present.

As I note in the book, “Although there are some exceptions, most cities reach their creative peak during periods of peace. Most centers of progress also thrive during times of relative social, intellectual, and economic freedom, as well as openness to intercultural exchange and trade. And centers of progress tend to be highly populated. . . . Identifying those common denominators among the places that have produced history’s greatest achievements is one way to learn what causes progress in the first place. After all, change is a constant, but progress is not.”

From the fall of the Berlin Wall to Hong Kong’s transformation from a war-ravaged “barren island” into a prosperous metropolis, many of the stories featured in Centers of Progress hold valuable lessons about the importance of ideas, people, and freedom. I hope that you will consider joining me on a journey through the book’s pages to some of history’s greatest centers of progress.

Today marks the 39th installment in a series of articles by HumanProgress.org called Centers of Progress. Where does progress happen? The story of civilization is in many ways the story of the city. It is the city that has helped to create and define the modern world. This biweekly column will give a short overview of urban centers that were the sites of pivotal advances in culture, economics, politics, technology, etc.

Our 39th Center of Progress is Houston during the 20th century Space Race, the famous period of rivalry between the United States and the Soviet Union over which nation could achieve more in the realm of space exploration. Nicknamed “Space City” because it houses NASA’s famed Mission Control Center, Houston has done more to advance space exploration than any other city.

Today, as the fourth most populous city in the United States (beaten only by our previous Centers of Progress New York, Los Angeles and Chicago), Houston is a sprawling, busy port city. As the largest city in Texas and in the country’s South, Houston is also a thriving center of regional cultural traditions and boasts the world’s largest livestock exhibition and rodeo. The Houston Rodeo draws millions of visitors annually and has attracted famous musical performers over the years ranging from Elvis Presley to Beyoncé Knowles. But the city is also increasingly multicultural. More than 20 percent of today’s Houstonians were born abroad, with particularly large populations hailing from India, Vietnam, China (the city has its own flourishing Chinatown), Africa, and Latin America.

Houston also has the distinction of being the largest city in the country without zoning regulations, which its voters have repeatedly rejected, giving the city a reputation for laissez-faire land management. Houston’s lack of zoning has led to many businesses and houses coexisting as neighbors, creating unusual juxtapositions—and relatively affordable home prices, even as the city’s population has nearly doubled since 1970, swelling to 2.3 million. As the writer Nolan Gray has noted, unzoned Houston is “able to grow, adapt, and evolve like no other city” with an “ongoing supernova of construction.” Perhaps America’s most affordable metropolis, Houston is a car-centric city stretched over a vast flat landscape. Houston is also a major cultural and culinary destination known for its numerous museums and restaurants, as well as its large zoo and, of course, the Space Center—the area’s top attraction for international tourists.

Reports from European explorers suggest that native tribes such as the Akokisa people once lived in what is now the Houston area. The site was sparsely inhabited in 1826, when the settler John Richardson Harris (1790–1829) founded a town within the bounds of what is now Houston and named it Harrisburg after himself. A decade later, Harrisburg was destroyed during the Texas Revolution by Mexican troops pursuing the Texas army. A week later, the Battle of San Jacinto (1836) took place about 20 miles east of present-day Houston, ending the war, and Texas gained its independence from Mexico.

The people of the newly independent Republic of Texas (1836–1846) built a town with access to the Galveston Bay navigation system to serve as a transportation hub and temporary capital. Two enterprising brothers from New York state, the investor John Kirby Allen (1810–1838) and mathematics professor-turned-businessman Augustus Chapman Allen (1806–1864), who together had worked to keep supply channels operating during the war, bought land on the banks of Buffalo Bayou for the new town. The brothers thus became the founding fathers of Houston.

The site took its name from the Virginia-born military leader, statesman, and Cherokee citizen (by induction, not birth) Sam Houston (1793–1863), who led the Texas army to victory against Mexico and was heralded as a war hero. His accomplishments over the course of his life included serving as president of the Republic of Texas, representing Texas in the U.S. Senate, becoming governor of Tennessee (although he resigned early to live among the Cherokee), and governor of Texas. He remains the only individual to ever serve as the governor of two different states.

The city of Houston served as the congressional meeting place for the Republic of Texas (1836–1846) from 1837 to 1839, when the capital moved to Austin. In 1846, Texas was formally admitted as a state within the United States, and by 1850, the first census year after Texas joined the United States, there were 2,396 Houstonians. Two decades later, that figure had grown to 9,332, and the U.S. Congress designated Houston as an official ship port. Improvements to the ship channels helped Houston thrive as a trade hub.

In 1900, disaster struck the nearby town of Galveston. A Category 4 hurricane killed between 8,000 and 12,000 Galvestonians, making it the deadliest hurricane in U.S. history to this day. Many fled inland from the ruins of the devastated Galveston, moving to Houston. The following year, oil was discovered at Spindletop, some 80 miles east of Houston. More oil was discovered in Humble, about 20 miles northeast of Houston, in 1905 and in Goose Creek, about 25 miles east of Houston, in 1906. Houston’s location made it a natural choice to develop oilfield equipment.

Between the influx of new residents after the hurricane and the city’s proximity to several oil site discoveries, Houston’s economy grew rapidly. In 1912, Rice University was founded. In 1925, the 25-foot-deep Houston Ship Channel was completed, and Houston’s port welcomed its first deep-water vessel, making the city a gateway of global trade. Houston became Texas’s most populous city by the 1930 Census, with 292,352 residents. The city’s efficient maritime shipping made Houston rich as the Texas oil industry grew in the 1920s and 1930s, with more and more oil refineries popping up along the Houston Ship Channel. By the late 1940s, Houston’s port was the second busiest in the country, ranked by tonnage of goods transported, and by the mid-1950s Houston’s population had swelled to a million residents.

But the 1960s are when Houston’s greatest contributions to humanity began, as the city became the site where flight controllers on Earth would direct astronauts to the final frontier. After American engineer Robert Goddard (1882–1945) invented high-flying liquid-fueled rockets and American physicist J. Robert Oppenheimer (1904–1967) oversaw the first atomic bomb detonation in 1945, competition in the arena of rocketry between the Soviet Union and United States soon extended into spaceflight. The Soviet launch of the first satellite, Sputnik 1, in 1957 prompted the United States to create the National Aeronautics and Space Administration (NASA). In 1961, the Soviet lead in the Space Race grew more pronounced when the USSR launched the first man into space, Yuri Gagarin (1934–1968) in a spacecraft called Vostok 1.

That year, after a lengthy search, NASA selected Houston as the location for a new manned spaceflight laboratory because of the city’s mild climate, land availability, water supply, easy access to a major port, well-established industrial production capacity, and the presence of a large research university (Rice University), among other factors. The fact that the vice president at the time, Lyndon B. Johnson (1908–1973), was a Texan, may have also helped. Construction broke ground in 1962. In an address that year at Rice University, President John F. Kennedy stated:

We meet at a college noted for knowledge, in a city noted for progress, in a State noted for strength, and we stand in need of all three. . . . This city of Houston, this State of Texas, this country of the United States was not built by those who waited and rested and wished to look behind them. This country was conquered by those who moved forward—and so will space. . . . What was once the furthest outpost on the old frontier of the West will be the furthest outpost on the new frontier of science and space. Houston, your City of Houston, with its Manned Spacecraft Center, will become the heart of a large scientific and engineering community.

The Manned Spacecraft Center facility formally opened in 1963 and was renamed the Lyndon B. Johnson Space Center in 1973 after Johnson’s death. The center’s famed Mission Control Center has guided every American human space mission since Gemini IV in 1965 and manages the U.S. portions of the International Space Station today. When speaking remotely with the “CAPCOM” (the member of the operations team on the ground in charge of communications) in the Mission Control Center, astronauts refer to it by its radio call signs “Mission Control” or, simply, “Houston.”

While Gemini IV launched from Florida like most NASA missions, Houston assumed flight control the moment the spacecraft left the launch tower and entered the sky. The flight controllers in Houston monitored every aspect of the mission, including the spacecraft’s trajectory and fuel and oxygen levels as well as the crew’s heart and breathing rates. Leading them all was the flight director—the “orchestra leader,” as one retired flight controller put it. NASA refers to Houston as the “nerve center for American human spaceflight.” Gemini IV was NASA’s second manned Gemini spaceflight mission; it sent astronauts to orbit the Earth at a high altitude. It involved the first “spacewalk” (astronaut activity outside a spacecraft) by an American—less than a year after the Soviets achieved the first spacewalk—and conducted many science experiments.

In 1967, Houston officially adopted the “Space City” moniker. Flight controllers in Houston guided groundbreaking missions, including Gemini VIII in 1966, which saw the first successful spacecraft docking, and Apollo 8 in 1968, the first crewed mission to reach the moon and orbit it before returning to Earth. The latter’s astronauts became the first people to view the entirety of the Earth from afar, a sight captured in the remarkable “Earthrise” photograph. The crew also issued a captivating Christmas Eve broadcast, reading from the Book of Genesis. More people tuned in to listen to the astronauts’ voices than had ever simultaneously heard any voice in history. But Houston’s crowning achievement during the Space Age was undoubtedly the Apollo 11 mission in 1969, when human feet first stepped on the moon.

Astronaut Neil Armstrong’s (1930–2012) words upon touching down on the lunar surface are now famous: “That’s one small step for man, one giant leap for mankind.” But they were directly followed by a line directed at Houston’s eponymous Mission Control, “Houston, Tranquility Base here. The Eagle has landed.” Around 600 million people, a fifth of the global population at the time, watched the landing live, including north of 85 percent of U.S. households. People alive at the time often vividly recall where they were during that “giant leap for mankind.”

The eyes of the world were on the astronauts planting an American flag on the moon. But in a windowless room, stationed in rows behind console screens relaying critical data, mostly wearing white-collared shirts with skinny ties and pocket-protectors, the flight controllers in Houston were the quiet heroes of the Space Age. Their pale gray IBM consoles provided some 1,500 items of ever-changing information for analysis. Because the presence of flight controllers was required around the clock during multiday missions, each role was fulfilled in four overlapping eight-hour shifts by multiple people. At the time of the first moon landing, the average age of the flight controllers in Houston was only 32, with most having studied engineering, mathematics, or physics. The main flight director was Cliff Charlesworth (1931–1991), who held a bachelor’s degree in physics and was in his late 30s.

NASA’s Houston facility houses more than just Mission Control; it also once contained the Lunar Receiving Laboratory, where the first men to walk on the moon spent time quarantining upon their return to Earth, and most lunar rock samples are stored in Houston to this day. Houston also serves as a base for astronaut training.

While crew safety always took precedence over mission success, space exploration and astronaut training are dangerous endeavors, and astronaut deaths occurred, such as that of Theodore Freeman (1930–1964), who died during astronaut training in Houston due to a bird strike. Houston takes part in NASA’s annual commemoration of fallen astronauts. In a contrast of values, the Soviet government infamously concealed many space program deaths for decades, such as that of Mitrofan Nedelin (1902–1960), who perished in a covered-up launchpad explosion along with over 100 other people, and the Ukrainian pilot Valentin Bondarenko (1937–1961), who died during cosmonaut training at age 24.

In 1970, Houston’s management skills were put to the test like never before when Apollo 13, the third attempted moon landing mission, suffered an oxygen tank explosion. Soon after, astronaut Jim Lovell (b. 1928) spoke the now-famous line, “Houston, we’ve had a problem here” (better-known in the shortened form, “Houston, we have a problem” from the 1995 film Apollo 13 that dramatized the incident).

The explosion damaged the spacecraft and made a moon landing impossible. Houston’s attention turned to getting the astronauts back to Earth alive. With the command module’s life support system failing, the crew moved to the lunar module. That module was only intended to support two men for two days, but thanks to innovative thinking from the team in Houston, new procedures allowed the lunar module to support three men over the course of four days. The flight director, Gene Kranz (b. 1933), chose a return route to Earth that involved looping around the moon, and Houston’s Manned Spaceflight Center director Robert Gilruth (1913–2000) made decisions regarding the last part of the return journey that resulted in the safe landing of the astronauts in the Pacific. The actions of both the astronauts and the ground crew in Houston were essential to averting loss of life.

All in all, NASA completed six successful missions landing humans on the moon, with the last being Apollo 17 in 1972. Twelve humans have walked on the moon, and all have been American astronauts whose missions were guided by Houston. The last words spoken on the moon came from astronaut Gene Cernan (1934–2017) and were, “We leave as we came and, God willing, as we shall return, with peace, and hope for all mankind.”

Despite that rhetoric emphasizing unity, international rivalry was a major factor motivating space exploration. After the Cold War’s end, the space industry was no longer subject to the intense competition that drove progress during the Space Race, and crewed space exploration stagnated. As of this writing, only four moonwalkers remain alive, ranging in age from 86 to 92. But a new era of private space endeavors, led by companies such as SpaceX, Blue Origin, and Virgin Galactic, may once again allow humanity to reach for the stars as profits drive a new space race. Nearly 400 miles southwest of Houston, near the southernmost tip of Texas, SpaceX has constructed its own spaceport, Starbase. Today, Houston also houses an urban commercial spaceport that is expanding as Space City seeks to position itself as a hub not just for NASA activity but for private spaceflight.

Houston grew from a war-ravaged, struggling trading post into a global oil shipping nexus and then the capital of the Space Age. From liftoff onward, the American astronauts who shattered records and tested the limits of the possible relied on Houston to ensure mission success and bring them safely home. Many people still consider the moon landing to be among the greatest achievements of humanity. It was certainly the greatest feat of exploration in history. For guiding mankind to the final frontier, Houston has landed as our 39th Center of Progress.