James William Loewen was an American sociologist, historian, and author. He was best known for his 1995 book, Lies My Teacher Told Me: Everything Your American History Textbook Got Wrong. A 2005 book, Sundown Towns: A Hidden Dimension of American Racism, galvanized a national effort to develop a list of sundown towns.

Sundown towns, also known as sunset towns, gray towns, or sundowner towns, are all-white municipalities or neighborhoods in the United States and Canada that were most prevalent before the mid-20th century, which practiced a form of racial segregation by excluding non-whites via some combination of discriminatory local laws, intimidation or violence. The term came into use because of signs that directed "colored people" to leave town by sundown.