Rex Terry was born in Sturgis, Dakota Territory, and attended public schools and business college in the early 1900s. He began his career in retail in Fort Pierre, South Dakota, and later managed the Fort Pierre National Bank. Terry held leadership roles in the community, including serving as president of the Fort Pierre Commercial Club and Commissioner of Fort Pierre. He spent seven years in the South Dakota Senate and subsequently served as Lieutenant Governor for six years under Governors George T. Mickelson and Sigurd Anderson.

Rex Terry's political identity is shaped by a blend of local business acumen and fraternal community service, which informs his legislative approach. His tenure in retail and banking juxtaposes with his political career, suggesting a pragmatic yet principled stance on economic issues. Terry's leadership within the Masons and the Fort Pierre Commercial Club indicates a deeply rooted commitment to civic duty and local governance. His legislative record reveals an intriguing convergence with opposing factions on certain policies, hinting at a highly localized and calculated strategy.