Complex sentence: The fort, which was near the location of what is presently the intersection of PA Route 145 and Chestnut Street, stood until about 1940 and its location is today commemorated by a Pennsylvania Historical and Museum Commission marker.
Split into simpler sentences: The fort, which was near the present intersection of PA Route 145 and Chestnut Street, stood until about 1940. The site is commemorated by a Pennsylvania Historical and Museum Commission marker.