In 1921 George D Rosensteel opened the Gettysburg National Museum. It was a family business and passion. The collections from this museum are the foundation for the museum now located in the Gettysburg Military Park Visitors Center.
George D Rosensteel was the nephew of John Rosensteel. John grew up in the Gettysburg area, and began collecting relics of the battle, within days of the battle's ending. George worked for his Uncle, who owned and ran a series of businesses located on the east side of Little Round Top, which included a museum.
George opened the new Gettysburg National Museum in 1921. He built the museum on land bought from his Uncle, across the Taneytown Road from the Soldiers National Cemetery. He added to his collection of artifacts by buying other collections such as his Uncle's Rosensteel's Round Top Collection, the William Zinkand Collection, The Bushman Collection, The Henry Spangler Family Collection and others. Over the years the building was expanded so family could live there, house the ever growing collection of Civil War relics, and in 1963 the addition of an Electric Map.
In the early 1970's the property was sold to the National Park Service. Over 30,000 artifacts were donated to the Park Service at the same time. The government operated the building as the Gettysburg Visitor Center and Museum until 2008. On the last day of operation; 13 April 2008, about 160 people sat through the final showing of the Electric Map. The building was torn down in March 2009, to make way for rehabilitation of Ziggler's Grove.