Thousands of people commute between Baltimore and Washington every day. Although the cities are rivals in many ways, it makes sense to think of Baltimore and Washington as twin cities like Minneapolis-St. Paul and Dallas-Fort Worth.

Just for fun (really, let’s not take this too seriously) let’s pretend that Baltimore and Washington — just the city proper, not the suburbs — were somehow combined into a single contiguous city called Washmore. What would that city be like?

Population

The 2018 population of Washmore would be 1.305 million people, the 10th largest in the US. It would rank just below Dallas, Texas, and just above San Jose, California.

Washmore compared to its peer cities

This population would be spread out over 161 square miles, an area comparable to Wichita and New Orleans.

Washmore’s 161 square miles is fairly typical for a city with its age and population. Philadelphia, another large old city, has 142 square miles. Dallas and San Jose are newer which means they were built around cars; newer cities tend to be more spread out. They are 386 and 181 square miles respectively.

By contrast, the three largest cities in the US, New York, Los Angeles, and Chicago, all have far more land area than Washmore: 305, 503, and 234 square miles respectively.

If Washmore’s three largest suburbs were annexed into the city limits, its population would increase by about half a million, and its area would increase by 74 square miles

Washmore would then become the 5th largest city in the US, below Houston (2.3 million) and above Phoenix (1.66 million).

However, both of these cities have an area well over 500 square miles (and both are growing far faster than Washmore). If Washmore’s city limits could be expanded to around 500 square miles, it could incorporate 75% of Fairfax County, VA. This would increase Washmore’s population to about 2.7 million, the fourth largest in the US, just under Chicago (and with a far faster growth rate).

It would be fun to estimate the population of every major city if its area were expanded to 500 square miles, but I’ll let someone else work those numbers. In the meantime, let’s explore Washmore a bit more.

Population Density

Washmore’s population density would rank on the high end for large American cities (which are notoriously unwalkable), but it would be relatively unimpressive at 8,140 people per square mile.

Baltimore’s lack of population density drags down Washmore’s numbers: Washington is one of the densest and most walkable large cities in the US with 11,367 per square mile. But Baltimore’s density is just 7,561 and falling along with its population overall.

Washington, D.C. could be a lot denser, and its population much higher, but its strict building height restrictions severely limit its potential for density, and contributes to its extremely high housing costs. So many people are forced to commute from the suburbs that D.C.’s population increases by a staggering 79% during the workday; no other city has such an extreme proportion of commuters.

If Washmore abolished D.C.’s height restrictions, population density would likely dramatically increase. If 70% of DC’s commuters in 2013 were able to move to Washmore, its population would grow by at least 409,080. In this case, Washmore’s population density would substantially increase to 10,690 people per square mile.

And imagine what Washmore’s skyline would look like if Washington’s height restrictions were removed. It would surely be one of the most dramatic in the world.

Population growth: 1950 to 2018

Washmore’s population would have peaked in 1950 at 1.762 million. It would have been the 7th largest city in the US, ranking right below Detroit (at 1.9 million) and right above Cleveland (at 0.9 million). Washmore would be one of the most-declined cities in the US, with a population loss of 25% and almost 500,000 people.

By contrast, Washmore’s 2017 peer cities have experienced astounding growth since 1950. Dallas was a very young city in 1950, and San Jose was merely a large town. But the following decades were very good to both cities: both of are experiencing a century of dramatic growth.

But 1950 was, well, 69 years ago. What does population growth look like now?

Population growth: 2010 to 2018

Baltimore was the second fastest shrinking large city in the US in 2017, second to Detroit. In fact, Baltimore’s population since 2010 has been passed by an astounding nine cities:

DC, on the other hand, is one of the fastest growing cities in America, and it’s growing faster than Baltimore is shrinking. So Washmore’s population growth since 2010 would be above average, but not particularly dramatic compared to its peer cities.

What would life be like in Washmore? Let’s start with the average person’s first concern: safety.

Crime

It’s no secret that Baltimore is one of the most dangerous cities in the US with the third highest crime rate of 2017, and at #24, Washington is also fairly dangerous.

Washmore would be the 11th most dangerous city in the US with a weighted average of 1,324 crimes per 100,000 residents. It would have the 6th highest murder rate.

Economy

Baltimore is the largest city in the United States without a single fortune 500 company. Washington, DC city limits, however, is home to two such companies. Washmore, therefore, would only have two fortune 500 companies. This compares poorly to other cities in the million-plus population range: Dallas is home to nine fortune 500 companies; San Jose is home to four.

Of course, D.C.’s economy is based primarily on federal employment, and has the one of the highest median incomes of county equivalents in the United States at $82,372. Baltimore City’s median income is far less at $42,665, ranking among the poorest large cities in the U.S. Washmore, therefore, would have a median income of around $62,000, a respectable but unremarkable figure.

Diversity

According to WalletHub.com, both Baltimore and Washington rank on the low end of diversity among large cities. Out the 60 largest cities in the US, Baltimore is the 7th least diverse, while Washington is slightly more diverse than the American average. Exact estimates would require a deeper dig than I have time for at the moment, but here are some ballpark figures.

I averaged the diversity scores, and found that Washmore would be just the 42nd most diverse of the 60 largest cities in the US with below-average diversity, between Miami and Virginia Beach.

The largest ethnic group would be Black/African American, making up roughly 56% of the population. The second largest group would be non-Hispanic whites, making up about 32.4% of the population. These two groups would account for 88.4% of the city’s population, leaving not a lot of room for other minority representation.

It’s noteworthy, though, that four of Washmore’s suburbs are among the top 10 most diverse cities in the U.S.: Gaithersburg, Germantown, Silver Spring, and Rockville. All four cities are in Maryland.