[5] From then until the Great Depression, Calvin served as a busy trade center for the area's produce.

A ferry operating across the Canadian River gave access to Calvin's cotton market and railroad connections.

The Missouri, Oklahoma and Gulf Railroad (M, O &G) [b] constructed a line through the area, reaching Calvin in 1909.

By that time the growing town offered the surrounding agricultural community a choice of four cotton gins, eight general stores, two hotels, and numerous other businesses typical of the era.

U.S. Route 270 comes in with US 75 from the north but turns east at Calvin and leads 30 miles (48 km) to McAlester.

Oklahoma State Highway 1 runs through the center of Calvin, leading east with US 270 to McAlester and west 31 miles (50 km) to Ada.

According to the United States Census Bureau, the town of Calvin has a total area of 0.50 square miles (1.3 km2), all land.