Map of US highway 13 and family, and US 15 with US 220

US 13 is represented by the purple line from Morrisville PA to Eastover NC.

US 113 is the blue line beginning in Pocomoke City MD. Its current northern terminus is in Milford DE; the red line north from there to Dover is the historic extent of US 113.

US 213 (historic) is the red line from Ocean City to Elkton MD (west of Wilmington DE).

US 15 is the purple line beginning in Walterboro SC. Its current northern terminus is in Painted Post NY; the red line north from there to Rochester is the historic extent of US 15. Its original route to Rockingham NC is shown in red, as is its historic routing through Raleigh.

US 220 is also shown on this map (the blue line from Waverly NY to Rockingham NC). This is a north/south branch route misnumbered as if it runs east/west, so I included it on this map to demonstrate how the highway would fit into the US 15 family, if it were to be assigned a number US x15. You can also view the US 20 map, which shows US 220 with its implied family.