US immigration trends shifted dramatically between 1850 and 2013 —including changes in the dominant countries of origin for each state and decade, and the total size of foreign-born population — according to a new series of historical maps from the Pew Research Center.

There's no argument about the fact that immigrants have consistently played an important part in American history, but the maps, based on recent US Census data, reveal lesser-known facts about immigrant population rate changes over time. The census shows us that different decades saw changing sizes of non-US-born populations. Compare, for example, the largest immigrant populations by country of origin in 1900, 1950, and 2000.

In 1900, 2.7 million Germans made up the largest total percentage of immigrants.

By 1950, an estimated 1.5 million Italians comprised the largest group of immigrants that year, more than a million less than the largest group (Germans) in 1900.

In 2000, 9 million Mexicans accounted for a population size that's six times larger than the largest group (Italians) in 1950.

There's yet another story the maps don't help visualize, though — the ebb and flow of foreign-born residents as part of the total US population, which was the lowest in 1970 (4.7 percent) and highest in 1890 (14.8 percent), which we calculate here:

The percentage of foreign-born residents today is closer to that of 1900 than 1990. If the number of foreign-born residents in the US feels like it's shifting to you, you're spot on — but only when you compare it with what you've been alive to see in your lifetime.