Lawrence Washington was born in Virginia and was a mentor of sorts to his more famous half-brother George Washington. Lawrence was educated in England, where he was recruited into the Templar Order by Grand Master Reginald Birch. Lawrence returned to Virginia in 1738 to oversee his father's plantation on the Potomac River, and also to seek out Precursor relics.
In 1739, the British Parliament created an infantry for its American colonies, to be used in their conflict against Spain in the West Indies. Lawrence Washington arrived in Jamaica in 1741 and saw action in expeditions against Cartagena, New Granada, Cuba, and Panama. Many casualties in these conflicts were the result of disease rather than violence. Because he arrived in the tropics early, he managed to survive fevers that decimated the other American colonists. Upon his return to the American colonies, Washington became a militia commander at the rank of Major.
Washington married Anne Fairfax in 1743. In 1747, he, his father-in-law, and other prominent businessmen began to work together, with the goal of opening trade to the American interior.
Lawrence was diagnosed with tuberculosis and traveled to Barbados with his younger brother George in an attempt to help his health. George caught a minor case of smallpox and Lawrence used to opportunity to travel to Port-au-Prince on Templar business. Lawrence returned to his Mount Vernon home in July 1752, where he died from his disease. His younger brother George eventually inherited and took over management of the Mount Vernon plantation.