What were the top immigrant groups in the antebellum period?

During the antebellum period in the United States, the top immigrant groups included the Irish, Germans, and British. The Irish primarily immigrated due to the Great Famine in the 1840s, while Germans sought economic opportunities and political refuge. Other groups, such as Italians and Scandinavians, also began to arrive in smaller numbers, contributing to the diverse cultural landscape of the nation before the Civil War. These immigrants significantly influenced American society, economy, and politics.