HARRISBURG, Pa., March 17, 2011, /PRNewswire-USNewswire/ -- Innovations in agriculture, the discovery of a 12,000-year-old mastodon, the early days of the oil industry, and a community's challenge to the Fugitive Slave Act are among the 13 new historical markers approved by the Pennsylvania Historical and Museum Commission (PHMC) at its March 16 meeting. The new markers, selected from 54 applications, will be added to the nearly 2,200 familiar blue-with-gold-lettering signs that dot roads and streets across Pennsylvania. Since 1946, the PHMC's historical markers have captured the memory of people, places, and events that have affected the lives of Pennsylvanians over the centuries. The signs feature such subjects as Native Americans and settlers, government and politics, athletes, entertainers, artists, struggles for freedom and equality, factories and businesses, and a multitude of other notable topics. Nominations for historical markers may be submitted by any person or organization and are evaluated by a panel of independent experts from across the state and approved by PHMC commissioners at their spring meeting. More information on the Historical Marker Program including application information is available online at www.phmc.state.pa.us. The Pennsylvania Historical and Museum Commission is the official history agency of the Commonwealth of Pennsylvania. Media contact: Howard Pollman, 717-705-8639 Editor's Note: The following is a list of the newly approved state historical markers with the name of the marker, the location and a brief description: Camp Michaux, Cook Township, Cumberland County Formerly an iron ore mining site and CCC camp, it became a POW camp during World War II. It was used as an interrogation center to gather intelligence key to developing Allied military policies. Magdalena House/River Brethren, Conoy Township, Lancaster County Site of the establishment of the River Brethren denomination, subsequently Brethren in Christ, in the late 1770s. This sect is one of the earliest indigenous American religious denominations.