Another domestic problem during this period concerned the boundary dispute between Pennsylvania and Virginia. When the Penns colonized Pennsylvania, they claimed the 39th degree parallel as their southern boundary. Virginia, however, claimed all the territory as far north as the 40th degree parallel including the choice section of Fort Pitt (now the site of Pittsburgh). After Pennsylvania authorities had established courts at Hanna's Town (now Greensburg), Governor Dunmore of Virginia sent Dr. John Connelly to establish a rival court with competing magistrates in 1773. The struggle for ownership of this area was temporarily postponed during the American Revolution, although the Virginia courts continued to remain in session in western Pennsylvania from 1774 to 1780. Finally, negotiations took place, and an agreement was adopted to allow a survey to be made in the region and to accept a boundary recommended by the joint boundary commission. The Mason and Dixon Line was extended to the southwest corner of Pennsylvania in 1784; the western boundary line of Pennsylvania was permanently agreed upon in 1785-1786. In the following year, in December, an historical event took place which contributed greatly to science. James Rumsey, a native Marylander who had moved to Bath, Virginia (now Berkeley Springs, West Virginia), was interested in boat-building and in the possibility of steam propulsion. After the Virginia General Assembly had given him exclusive permission to navigate specific types of boats constructed by himself on the state waterways for ten years, he successfully transported six individuals for the first time in a steamboat four miles up the Potomac River near Shepherdstown. Rumsey continued to experiment with additional steamboats on the Potomac. In order to obtain financial assistance, he traveled subsequently to London and ironically died there before his second boat, the "Columbia Maid," had been completely constructed. This event occurred twenty years before Robert Fulton made his historic trip up the Hudson River in the "Clermont."