Bland was born in Prince George County in 1742 to a prominent family in colonial Virginia. His parents were Theodorick and Elizabeth (Bolling) Bland. His grandfather, Richard Bland had married Elizabeth Randolph. His uncle, Richard Bland, and his cousin, Peyton Randolph would precede him in the Congress. Theodorick was sent to Great Britain for education and studied medicine at the University of Edinburgh, graduating in 1763. He returned to Virginia and began a practice.
As the Revolution neared, Bland's Whig views aligned him with the rebels. In June 1776, he became a captain in the Virginia's cavalry. He eventually rose to become Colonel of the 1st Continental Light Dragoons, but his military career was not very noteworthy. A part of his problems was due to General Washington's generally poor use of cavalry. The other part was due to his own limitations in military leadership. His unit was relegated to scouting duty and he was later described by a distant cousin, Henry "Light Horse Harry" Lee, as "...noble, sensible, honorable, and amiable; but never intended for the department of military intelligence." In 1779, Bland returned to Virginia, for a few months in charge of the post at Charlottesville before leaving the military and going to New York.
In 1788, he was a delegate to the Virginia Convention called to ratify the United States Constitution. Bland was opposed to ratification as yielding too much power to a central government. Yet when the constitution was adopted, he was elected to the First United States Congress, and he served in the House of Representatives from March 4, 1789 until his death in 1790. He died while attending the Congress in New York City.
Bland was the first member of Congress to die in office. William Branch Giles completed his term. Bland was originally buried in New York's Trinity Churchyard. In 1828, his remains were moved to the Congressional Cemetery in Washington, D.C..