For most of its first 150 years, Florissant was a small place. Founded in 1786 and incorporated as a city in the 19th century, the village had grown slowly but steadily on the strength of agriculture, the Catholic parish, and trade with the nearby river towns. The 20th century changed that completely. By the 1970 census, Florissant had grown to tens of thousands of residents and become one of the largest cities in St. Louis County. Few American suburbs grew faster, and few combined that growth with as much continuity to their pre-modern roots.
This is the story of how that happened — a story driven by Lambert Field, McDonnell Aircraft, post-war suburbanization, civil rights pressures, and a community that managed to preserve its Old Town center even as the surrounding valley filled in.
The slow decades: 1900-1940
The first four decades of the 20th century brought modest change to Florissant. The town added paved streets, electric service, and modern utilities. The Old St. Ferdinand Shrine remained the center of community life, with the parish school, several civic groups, and the mostly Catholic population continuing patterns established in the previous century. Population grew, but slowly — staying well under 2,000 residents through the early decades of the century, according to U.S. census records.
What changed during this period was not Florissant itself but its surroundings. Lambert Field, immediately south of Florissant in present-day Berkeley, was developed beginning in 1920. The St. Louis aviation industry took shape around the airfield. By 1939, McDonnell Aircraft Corporation, founded by James S. McDonnell, was operating from Lambert. World War II was about to multiply that operation many times over.
World War II and the McDonnell expansion
McDonnell Aircraft expanded dramatically during World War II to meet military demand for combat aircraft. The Lambert Field operations grew from a few hundred employees to many thousands. Workers needed housing. The undeveloped agricultural valleys north of the airport — the Florissant Valley — became the obvious answer.
Even before the war ended, developers were buying farmland in the valley and laying out subdivisions. The post-war construction boom made what had been a slow trickle of new homes into a flood. Veterans returning from service used GI Bill financing to buy starter homes; growing families sought single-family houses with yards; and the wave of suburbanization that transformed metropolitan America landed squarely on Florissant.
The 1950s and 1960s: explosive growth
Florissant's population grew explosively in the 1950s and 1960s, multiplying many times over in a single generation, according to U.S. census records. The city annexed surrounding farmland aggressively to accommodate new subdivisions. Where there had been corn fields in 1945, there were ranch homes by 1965.
The economic engine remained McDonnell Aircraft, which continued to grow through the Korean War, the Cold War, the development of the F-4 Phantom and other major military aircraft, and (after McDonnell merged with Douglas Aircraft in 1967) commercial aviation. McDonnell Douglas employed tens of thousands of workers across the metro area, and a substantial fraction of them lived in Florissant or the surrounding north St. Louis County suburbs.
School construction kept pace with population. The Hazelwood, Ferguson-Florissant, and other school districts built new schools steadily through the 1950s and 1960s. McCluer High School, on the grounds that include the historic Taille de Noyer mansion, became one of the largest schools in the region. The University of Missouri–St. Louis was founded in 1963 just south of Florissant on a former country club, providing higher-education capacity for the growing population.
The civil rights era in north St. Louis County
Florissant’s explosive 1950s and 1960s growth coincided with the civil rights era and with the racial restructuring of the St. Louis metropolitan area. Like many American suburbs of the period, Florissant grew predominantly as a white suburban community, with patterns of racially restrictive lending, housing covenants (formally illegal after 1948 but informally persistent), and de facto segregation that shaped who could live where.
The surrounding north St. Louis County region experienced significant demographic change beginning in the 1970s and accelerating in subsequent decades. Communities including Ferguson, Berkeley, Black Jack, and Spanish Lake saw substantial demographic shifts; school district enrollments changed; and the broader region grappled with questions of integration, school funding, and equal access to opportunity that continue to shape the area today.
Florissant itself has become a meaningfully more diverse community over the past several decades. The 2020 census reflects a city that, while still majority-white, includes substantial Black, Hispanic, and Asian populations and has worked to build civic structures that engage all of its residents.
The end of the McDonnell era and modern Florissant
McDonnell Douglas remained a dominant employer through the 1970s, 1980s, and 1990s. Boeing acquired McDonnell Douglas in 1997, and the former McDonnell facilities at Lambert continue to operate as Boeing's St. Louis defense facility, building the F-15, F/A-18, and other military aircraft. Boeing remains one of the largest private employers in the region.
The base of Florissant’s economy has diversified beyond aerospace over the past several decades. Healthcare (BJC and SSM systems), retail, education, and small business now account for a substantial share of local employment. Population has stabilized at roughly 50,000 — down from the 1970 peak as suburban growth shifted further outward into St. Charles County, but still one of the largest cities in the metro area.
Preservation of Old Town
Through all of the suburban expansion of the 20th century, Florissant’s Old Town historic district remained intact. Local preservation groups, the Florissant Valley Historical Society, and the city government have worked to protect the colonial-era buildings, the original village street grid, and the architectural character of the original Fleurissant Valley village. The result is something genuinely unusual in suburban America: a working town with a real, intact 18th-century core.
Today, residents of newer subdivisions can walk to a Catholic shrine on its original colonial-era site. They can drive past Casa Alvarez, an 18th-century stone house, on their commute. They can take their children to a high school whose campus includes a colonial-era French mansion. The continuity is part of what makes Florissant distinctive.
The 21st century
Modern Florissant is a stable, mid-sized Missouri suburb with deep roots and active civic life. The city hosts several annual festivals (the Fall Fest, the Valley of Flowers Festival in spring, an Old Town Christmas walk), a busy parks system, and a network of small businesses and professional services. Issues facing the community — school district performance, housing affordability, infrastructure renewal, regional economic competitiveness — mirror those facing other inner-ring American suburbs.
For visitors, Old Town Florissant remains the destination. For residents, the city is a working community with a remarkable history quietly woven into its everyday geography.
A firm with deep Florissant roots
David Naumann & Associates has practiced in Florissant since 1979, a small but real part of the community's late-20th-century life. For more on the firm's roots in north St. Louis County, see our Florissant attorney page or the founding of Florissant and Old Town landmarks articles.
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