A strengthening U.S. economy has spurred the largest pickup in immigration since before the recession, driven by Asian newcomers and a gain in Hispanic arrivals.

The number of foreign-born people in the U.S. grew by 523,400 last year, according to the Census Bureau. That beat the previous year’s net gain of roughly 446,800 and is the biggest official jump since 2006. The numbers don’t distinguish between authorized and unauthorized immigrants.

...