William N. Roach attended Gonzaga College High School and Georgetown University, establishing a solid educational foundation. He served as a clerk in the quartermaster's department during the Civil War, gaining early experience in public service. Roach later moved to Dakota Territory, where he became involved in mail contracts and held a position in the Territorial House of Representatives. He pursued a political career, including unsuccessful bids for governor and a Senate seat, ultimately serving in the U.S. Senate from 1893 to 1899. Despite facing allegations of embezzlement while a bank officer, no action was taken against him.

William N. Roach's political identity is marked by a calculated approach to regional interests, as evidenced by his unexpected alignment with opposing factions on environmental regulations. Despite facing allegations of embezzlement during his tenure as a bank officer, his political career continued without significant repercussions, suggesting a resilient yet controversial public persona. His legislative record hints at a strategic, perhaps even opportunistic, alignment with different political factions to advance specific regional objectives.