I was born during a period of historically low immigration in the United States. The percentage of foreign born Americans reached its nadir during my childhood.
This interactive map from Pew Research shows the predominant country of origin for the foreign-born residents of each state as reported during each census.
From the 1950s through the 1970s, the percentage of foreign-born Americans hovered around 5%. From the second half of 19th century into the first half of the 20th, the percentage was more typically in the 10% to 15% range. In the last few decades, the proportion of foreign-born Americans returned to historical levels. Being born when immigration levels were historically low may have given me a false impression of what is “normal.”