James Marshall Sprouse graduated from Williamson High School and went on to serve in the United States Army during World War II. He earned an Artium Baccalaureus degree and a Bachelor of Laws, followed by a Fulbright Scholarship in international law. Sprouse held various legal positions, including assistant state attorney general, counsel for the Displaced Persons Commission, and private practice. He served with the Central Intelligence Agency and later as a justice on the West Virginia Supreme Court of Appeals. Appointed to the United States Court of Appeals for the Fourth Circuit by President Jimmy Carter, he remained in this role until his retirement in 1995.

James Marshall Sprouse's career juxtaposes a judicial background with progressive political activism, revealing a penchant for influencing policy from behind the bench and the ballot. His strategic support of Charlotte Pritt's gubernatorial bid, despite his own electoral setbacks, suggests a commitment to advancing regional progressive causes. Sprouse's approach combines a respect for legal frameworks with a willingness to engage in grassroots political efforts, highlighting a nuanced understanding of both judicial and electoral dynamics.