Question

in the early 1800s, immigrants from ireland settled in the northeastern united states, resulting in
an increase in the strength of the union army.
their election to many government positions in the region.
calls for immigration restrictions by wealthy industrialists.
their competition with free african americans for menial jobs.

Explanation:

In the early 1800s, Irish immigrants often took low-wage, unskilled (menial) jobs. Free African Americans in the Northeast also relied on these types of jobs, creating direct competition between the two groups. The other options are incorrect: the Union Army did not exist until the Civil War (1861-1865), Irish immigrants faced discrimination and were not elected to many local government positions in this era, and wealthy industrialists generally welcomed cheap immigrant labor rather than calling for restrictions.

Answer:

their competition with free African Americans for menial jobs.