Rousas John Rushdoony (1916-2001) was an American theologian and writer known for his role in the development of the Christian Reconstructionism movement. He emphasized the application of Christian principles to all areas of life, including law, education, and government, advocating for a society governed by Biblical standards. Rushdoony founded the Chalcedon Foundation in 1965, which aimed to promote his ideas through publications and conferences. He is often credited with influencing the Religious Right and the broader Christian political landscape in the United States, particularly in the late 20th century.