At the time of his father's death in 1716, Mason was 27 and already a man of prominence in Stafford County. Like his father, Mason served as a colonel in the Stafford County militia and represented Stafford County as one of its two delegates in the
House of Burgesses continually between 1715 and 1726. During his tenure as a burgess in
Williamsburg, Mason met and married his wife Ann Stevens Thomson, whose family owned plantations in Maryland. Like his father and grandfather, this George Mason became Stafford's County Lieutenant of Stafford (in 1719), and also served as the county's
sheriff. Mason amassed enormous land holdings in Stafford,
Fauquier,
Prince William, and
Fairfax counties in Virginia. Mason also increased his land holdings by acquiring large grants south of the
Occoquan River, which were later named
Woodbridge by his grandson
Thomas Mason. Mason leased most of his properties out as smaller farms with their rent paid in
tobacco yield. Mason also earned income from fisheries and a ferry service carrying
King's Highway across the
Occoquan River. Because Mason owned land on both sides of the Occoquan River, he enjoyed a
monopoly on river crossings as well as on the fishing rights in
Belmont Bay. In 1716, Mason accompanied the "
Knights of the Golden Horseshoe Expedition" led by Lt. Governor
Alexander Spotswood across the
Blue Ridge and into the
Shenandoah Valley, where his famous son would invest. ==Marriage and children==