The tradition of protest songs in the United States is a long one that dates back to the 18th century and colonial period, the American Revolutionary War and its aftermath. In the 19th century topical subjects for protest in song included abolition, slavery, poverty, and the Civil War amongst other subjects. In the 20th century civil liberties, civil rights, women's rights, economic injustice, politics and war were among the popular subjects for protest in song. In the 21st century the long tradition continues.