US 15 Business continues north into the Emmitsburg Historic District, where the highway intersects MD 140 (Main Street) and passes St. Euphemia's School and Sisters' House. The business route veers northeast and crosses Flat Run before approaching its northern terminus at US 15. Traffic from northbound US 15 Business to northbound US 15 is required to follow the ramp to southbound US 15 and turn around at US 15's interchange with MD 140. US 15 Business continues north to North Seton Avenue, a service road that parallels the southbound direction of US 15 toward the Pennsylvania state line. That intersection is connected to a one-way southbound ramp from US 15's intersection with Welty Road. The intersection was changed to remove access from northbound US 15 Business to northbound US 15 in 2007. East of US 15, Welty Road immediately intersects Old Gettysburg Road, the old alignment of US 15 north towards Gettysburg.