PA 24 was designated in 1928 to run from the Maryland border south of Stewartstown north to US 111 (Old York Road) in New Market.

In York, the route was split into one-way pairs in the downtown area while US 111 Alternate (US 111 Alt.)

From the state line, the route heads to the northwest on two-lane undivided Barrens Road South and passes through agricultural areas with scattered residences.

PA 24 enters the borough of Stewartstown and becomes Main Street, heading north past homes.

Upon passing through the community of Rinely, the route crosses into North Hopewell Township and continues northwest through more rural areas on Winterstown Road.

[2][3] The road passes homes as it continues into the borough of Red Lion, where it turns north onto Main Street.

Past this intersection, the route continues past a mix of homes and businesses in the downtown area, passing west of the former Red Lion station along the abandoned Maryland and Pennsylvania Railroad line and coming to the PA 624 junction.

After an interchange with US 30, PA 24 enters commercial areas and passes to the east of the York Galleria shopping mall.

Past the mall, the route narrows back into a two-lane undivided road and heads northwest through a mix of wooded residential areas and some fields, passing through Mount Zion.

PA 24 makes a turn north onto an unnamed road and crosses the Codorus Creek into Manchester Township, passing a mix of residential neighborhoods and farmland.

[4] PA 24 was designated in 1928 to run from the Maryland border south of Stewartstown north to US 111 (Old York Road) in New Market.

The route followed its current alignment to Red Lion before it ran northwest concurrent with PA 74 to York.