Population of Montgomery County, MD: A Visual Journey

What does the population of Montgomery County, MD, look like when we go back to the earliest census data? Here’s the chart you’re expecting:

But this is only part of the story. After all, why did the population suddenly take off in the mid-twentieth century? And did the demographics of Montgomery County change, too? The answers are readily visible in the series of charts below.

Montgomery County, MD, in 1790

Maryland became a U.S. state on April 28, 1788. Thus, the 1790 census reveals Montgomery County as it was at this critical juncture in history—all 18,003 residents:

montgomery county demographics 1790

Montgomery County, especially southern Montgomery County, was a rural, tobacco-producing area that relied on slave labor. The slave population of Montgomery County rose in the early 1800s before declining in the decades leading up to the U.S. Civil War. Slavery was abolished in the United States after ratification of the Thirteenth Amendment on December 6, 1865:

slave population in montgomery county

Agriculture remained the primary industry of Montgomery County through the early- and mid-1800s. Census data regarding industry employment was inconsistent during these decades, but data as late as 1840 shows the heavy dependence on agriculture:

montgomery county employment by industry 1840

Montgomery County: The Big Transition

Looking at the very first chart of Montgomery County’s population growth, it’s easy to attribute the mid-twentieth-century rise to the Baby Boomers. But that would miss how exceptional the county’s growth was during that period.

In fact, Montgomery County vastly outpaced the population growth rate of Maryland in those decades:

montgomery county population growth rate
 

Why? For one, the Great Depression had a limited negative impact and ultimately accelerated population growth in Montgomery County. The county had little industry to lose when economic catastrophe struck, and Roosevelt’s New Deal greatly increased the number of federal government employees, many of whom settled in nearby Montgomery County.

Second, the National Institute of Health (NIH) relocated from its small Washington DC headquarters to more expansive structures in Bethesda. The federal research institute attracted private ventures, as the NIH provides federal grant money to private researchers.

This second factor was key in making Montgomery County’s exponential growth a remarkable increase in quality, as well as quantity, of residents.

Modern Montgomery County

Montgomery County’s population growth rate returned to levels on par with state growth after the 1960s. But the population continued to change in more subtle ways.

One perhaps surprising change is the consistent growth of older adults among Montgomery County residents:

montgomery county population by age
 

While we’re admittedly biased toward the idea of retiring in Montgomery County, there’s plenty of data to support the choice, from exceptional dining and shopping, to one of the nation’s highest education levels, to proximity to the nation’s capital.

Find out more about life in Bethesda at Fox Hill.