During the Civil War, like so many of their fellow citizens, Jews were forced to take sides. While most of the nation's 150,000 Jews lived in the North and supported the Union, a sizable minority numbering about 25,000 lived in the South and held strong allegiance to the Confederacy. Anti-Jewish sentiments rose sharply during the war, culminating in General Ulysses S. Grant's infamous Order No. 11, banning Jews as a class from Kentucky, Tennessee, and Mississippi. The order was soon rescinded at the request of President Lincoln himself.
From the nation's earliest days, an undercurrent of prejudice and discrimination posed a continuing challenge to the Jewish community. However, constitutional guarantees of religious liberty, backed-up by American Jewry's firm response to acts of intolerance, prevented persecution of Jews from sinking deep roots in the United States. Still, confronting the challenges presented by anti-Semitism has been a persistent concern of American Jewry and has led to the founding of communal organizations focused specifically on responding to prejudice and preventing it through education.
Sources: Abraham J. Karp, From the Ends of the Earth: Judaic Treasures of the Library of Congress, (DC: Library of Congress, 1991).