Not even three years ago, it seemed like there was still a long way to go before D.C. had more people than Baltimore.
At the time of the 2010 census, Baltimore had nearly 20,000 more residents than Washington: 620,961 to 601,723.
But Washington's growth has been booming for more than a decade, while Baltimore's population is stagnant.
The District gained more than 13,000 residents between July 2011 and July 2012. The U.S. Census Bureau on Thursday put D.C.'s population on July 1, 2012 at 632,323 -- up from 619,020 a year earlier.
In contrast, on July 1, 2011 Baltimore's population was estimated by the Census Bureau to be 619,493, down from 620,560 a year earlier.
Although the July 2012 population estimate for Baltimore will not be released until next year, trends indicate that Baltimore is far from keeping up with its southerly neighbor’s explosive growth.
That means this year, D.C.’s population most likely pushed past Baltimore's for the first time.
The July 1, 2012 estimate for Baltimore, which can be compared directly with the data released today about D.C., will be released with county-level date in March.
D.C.'s data is released earlier than Baltimore's because the national capital is treated as a state for Census Bureau purposes.
Maryland gained about 45,000 people over the past year, according to the Census Bureau estimates released Thursday. In terms of the raw number of people added during the 12 month period, Maryland was 13th among the states.
But that number puts the Free State in the middle of the pack, 23rd among the states, in terms of growth rate between July 2011 and July 2012.
The state's population grew 0.8 percent in that time. Maryland had 5,884,563 people on the July 1 estimate date, according to the Census Bureau. It continues to be the 19th most populous state in the union.
North Dakota grew the fastest during the July-to-July period, with its population increasing 2.17 percent. D.C. grew 2.15 percent, followed by Texas (1.67 percent), Wyoming (1.60 percent), Utah (1.45 percent) and Nevada (1.43 percent).
Except for North and South Dakota, all of the top ten fastest growing states were in the South or West, the Census Bureau said.
Two states lost population over the past year: Rhode Island and Vermont. Both lost less than 1,000 people, the Census Bureau estimates.
California is still the most populous state as of July 1, 2012, with 38 million residents. Texas was second (26.1 million) and New York third (19.6 million).
The U.S. population on July 1 was estimated at 313.9 million, an increase of 2.3 million (0.75 percent) over the 12-month period.
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