(December 2014) When the U.S. Census Bureau releases its 2014 state population estimates later this month, the new figures may confirm a demographic milestone: that Florida has passed New York as the third most-populous state in the United States.

The estimates for July 2013 put Florida's population at around 19.6 million, just 100,000 less than the population in New York. Between 2010 and 2013, the gap between New York's and Florida's populations narrowed by about 150,000 each year. Assuming this trend continued between 2013 and 2014, Florida has already passed New York as the third largest state.

Florida has undergone a century-long transition from the South's least populous state to a national demographic giant. Back in 1910, Florida had just 753,000 residents, which ranked it 33rd among the states (see table). By contrast, New York—the most populous state until California overtook it in the 1960s—had 9.1 million people in 1910, 12 times as many residents as Florida.

By 1950, Florida's population was nearly 2.8 million, large enough to rank it among the 20 largest states. Just one decade later, Florida had reached the top 10, and it has ranked fourth in population since the 1990 Census.

What caused Florida's rapid population growth? Over the course of the 20th century, Florida attracted millions of retirees moving from New York and other northern states. Job growth, especially in tourism and manufacturing, attracted new waves of domestic and international migrants and their families. The rise in home air conditioning also helped fuel a population boom in Florida and other southern states by enabling families to live there comfortably year round.

The effects of Florida's population growth go beyond bragging rights. As Florida's population has grown, so has its political clout. Congressional apportionment after the 1910 Census allocated the state a mere four seats in the U.S. House of Representatives—less than one-tenth the 43 seats that New York received (see table). But in each decade since 1950, Florida has gained at least two seats, while New York—whose growth rate has been well below the national average since the start of World War II—has lost at least two seats. The shift in political power from North to South was most striking during the 1980 reapportionment process, when Florida gained four seats and New York lost five (a nine seat swing). Currently, Florida and New York have equal political representation in Congress, as both states have 27 House seats.

Florida and New York, 1910-2013

  Population Rank No. of Seats in U.S. House of Representatives
Year Florida New York Florida New York Florida New York
1910 752,619 9,113,614 33 1 4 43
1920 968,470 10,385,227 32 1 4 43
1930 1,468,211 12,588,066 31 1 5 45
1940 1,897,414 13,479,142 27 1 6 45
1950 2,771,305 14,830,192 20 1 8 43
1960 4,951,560 16,782,304 10 1 12 41
1970 6,789,443 18,236,967 9 2 15 39
1980 9,746,324 17,558,072 7 2 19 34
1990 12,937,926 17,990,455 4 2 23 31
2000 15,982,378 18,976,457 4 3 25 29
2010 18,801,310 19,378,102 4 3 27 27
2013 19,552,860 19,651,127 4 3 27 27

Source: U.S. Census Bureau.

"Rankings matter for college football, but not so much for state population growth," notes Stanley Smith of the University of Florida's Bureau of Economic and Business Research. "Passing New York will not have any immediate impact on Florida's economy or political influence, but it's still an important milestone because it reflects many years of rapid population growth in Florida, and population growth has been a major driver of the state's economy. It's also significant for the U.S. as a whole because it is another marker of the continuing shift of the national population from the Northeast and Midwest to the South and West."

Even if the estimates for July 2014 keep New York ahead of Florida in the demographic derby, the Sunshine State is almost certain to pass the Empire State in population before the 2020 Census. And demographers expect Florida to pull further ahead of New York in the coming decades. The Bureau of Economic and Business Research projects Florida's population to exceed 25 million by 2040, while New York's 2040 population will fall below 20 million, according to projections from Cornell University.

Kelvin Pollard is a senior demographer at PRB.