In 1769, the "Bethesda Old Place Farm" home was expanded on the property and run as a tobacco-producing plantation with 26 slave workers. Mary Dorsey Pue inherited Belmont in 1771, and her husband Doctor Micheal Pue was appointed to run the county in 1775 (Anne Arundel). The estate was expanded again in 1830, struck by a tornado in 1858, and stayed in the Pue family until 1859. By 1943, the property had been subdivided to 237 remaining acres. In 1954, the Columbia Hills Corporation developed the land leaving just 7.3 acres surrounding the house. Howard Research and Development purchased most of the original Long Reach property between 1963 and 1966 for the development of Columbia.