The Mason-Tillett House, or Rock Hill, as it came to be known in the late-20th-century, is significant as a late-18th-century dwelling with an exceptional surviving interior, grained and marbleized woodwork, and an unusual physical plan. It is also significant as the probable location of the First Session of the Virginia Conference of the Methodist Episcopal Church in 1785 under Bishop Francis Asbury, founder of the Methodist Church in Virginia. Moreover, the participants debated Methodist support for the abolition of slavery and submitted a petition to the Virginia General Assembly advocating abolition throughout the Commonwealth. Later, Thomas Williams Mason, son of Nathaniel and Temperance Mason, was born and raised in the house. He served in the Confederate army from North Carolina, and after the war in both houses of the North Carolina legislature.  The Mason-Tillett House is located in far southeastern Brunswick County, near its boundaries with Greensville County and with North Carolina.