From here, US 13 enters the city of Wilmington and heads northeast along four-lane undivided South Heald Street. The road curves north into industrial areas and reaches a southbound ramp providing access to DE 9 a short distance to the east. After this, the road passes over Norfolk Southern's Shellpot Secondary railroad line on a bridge and intersects DE 9. Here, US 13 becomes concurrent with DE 9 and splits into a one-way pair following New Castle Avenue northbound and South Heald Street southbound, each carrying two lanes of traffic. The one-way streets traverse areas of urban rowhomes and businesses and merge on four-lane undivided South Heald Street. Along this stretch, US 13/DE 9 intersects the northern terminus of DE 9A. Following this, the road becomes East 4th Street and heads north-northwest across the Christina River on a drawbridge. US 13/DE 9 curves northwest and passes under Amtrak's Northeast Corridor railroad line, at which point northbound US 13 splits from the road by heading northeast on North Church Street at the grade crossing of a railroad spur. A block later, the concurrency between DE 9 and southbound US 13 ends at the point where southbound US 13 joins the road from North Spruce Street. US 13 continues along this one-way pair, carrying two lanes in each direction, through the eastern part of the city as it passes more urban development, heading to the west of Old Swedes Church and Fort Christina, which are both part of First State National Historical Park, on North Church Street. At East 11th Street, US 13 becomes two-way again and heads northeast over the Brandywine Creek on four-lane undivided Northeast Boulevard. Past the bridge, the route intersects East 12th Street and continues through urban residential and business areas as a four-lane divided highway.