R.J. Rushdoony was an American theologian, historian, and writer, best known for his role in the development of the Christian Reconstructionism movement. Born in 1916, he emphasized the application of Christian principles to all areas of life, including law, education, and government. His work sought to integrate faith with societal structures, advocating for a return to a biblical foundation in public life. Rushdoony authored numerous books, with his most influential work being Institutes of Biblical Law, published in 1973. He founded the Chalcedon Foundation in 1965, which aimed to promote his ideas and support the growth of a theocratic society based on Christian teachings. His legacy continues to influence various conservative and religious groups today.