The northern portion of PA 324 was chartered as the Lancaster and New Danville Turnpike in 1870, a private turnpike connecting New Danville to Lancaster. The present-day alignment of PA 324 was not designated as part of a legislative route when Pennsylvania first legislated routes in 1911. By 1926, the road between Lancaster and Martic Forge was paved while the portion between Martic Forge and Pequea was unpaved.
In 1870, the northern segment of PA 324 was designated as the Lancaster-New Danville Turnpike, a private highway connecting New Danville to Lancaster. It wasn't until 1911 that Pennsylvania established its first legislative routes, which did not include the current alignment of PA 324. By 1926, the stretch between Lancaster and Martic Forge had been paved, while the section between Martic Forge and Pequea remained rough.