The Chestnut-sided Warbler, Dendroica pensylvanica, is a New World warbler. They breed in eastern North America and in southern Canada westwards to the Canadian Prairies. They also breed in the Great Lakes region and in the eastern USA. These birds are migratory, wintering in Central America south to northern Colombia, and they are very rare vagrants to western Europe.
Edward Howe Forbush Useful Birds and Their Protection (Boston, MA: Massachusetts State Board of Agriculture, 1907)