Frank Martz, Sr., started Gray Line DC, Martz Group in 1908 with a 1912 White bus and a route that took him through small mining towns in Pennsylvania. During the Great Depression, the economic collapse inspired Frank and other independent carriers to create the National Trailways Bus System. This system became part of a national network with Greyhound lines, setting schedules and fares for connecting service across the country.
Through the years, the company has passed down from father to son. Today, Frank's great grandson, Scott Henry, helms the company of more than 400 employees, 250 coaches, and one magic-pumpkin carriage. Additionally, Martz boasts a travel agency and repair operations in Pennsylvania, Virginia, Florida, and Washington, DC, and operates sightseeing tours in Washington, DC, such as DC After Dark, Monticello & Thomas Jefferson Country, and the Spy City Tour.