U.S. Route 1 Business (US 1 Business) is a business route of U.S. Route 1 in the U.S. state of Maryland. The highway runs 6.90 miles (11.10 km) from US 1 and Maryland Route 147 (MD 147) in Benson north to US 1 near Hickory. US 1 Business is the old alignment of US 1 through Bel Air, the county seat of Harford County. US 1 was originally constructed on both sides of Bel Air in the early 1910s. The U.S. highway was widened in the 1920s, 1930s, and 1950s. US 1 Business was assigned to the highway from Benson through Bel Air to south of Hickory after the Bel Air Bypass was built in the mid-1960s. US 1 Business was extended north through Hickory when US 1 bypassed Hickory in 2000.