The US Census Bureau recently released its estimates of how the populations of America's counties and cities changed between July 1, 2013 and July 1, 2014.
The Census Bureau includes estimates of the different components of population change. One of those components is net international migration: the number of people who moved to an area from another country minus the number of people who left that area for another country.
International migration is a much smaller factor than other components for most counties. Only a small handful of counties lost population to international migration, and in most counties, immigration made only a very small dent in population change.
The biggest exceptions to this are the big cities on the East Coast, the San Francisco Bay area, and Florida, all of which saw immigration making a somewhat bigger impact on population growth.
Here's net international migration in each county, adjusted for 2013 population:
Here are the fifteen counties with the highest population-adjusted net international migration. Nine of these counties are either in Florida or near a big Eastern city:
