President Lincoln’s ancestors hailed from England, not Ireland, but he took the side of Irish Catholics and other immigrants when tensions flared between Catholics and the Know-Nothings.
The Know Nothings were a group of white, Protestant nativists who got their name because members were instructed to say “I know nothing” when questioned by police. Some lost their jobs to the influx of Catholic immigrants in the mid-1800s.
The tension led to riots in cities, and, eventually, the burning of two Catholic churches and a Catholic school in Philadelphia in 1844.
In 1855, Lincoln wrote his good friend Joshua Speed that, if the Know-Nothings ever took power, the Declaration of Independence would have to be amended to say that all men are created equal “except Negroes, and foreigners, and Catholics.”
“When it comes to this,” he wrote, “I should prefer emigrating to some country where they make no pretense of loving liberty – to Russia, for instance, where despotism can be taken pure, and without the base alloy of hypocracy.” (sic)
Source: National Park Service