Final answer:
John Adams was not part of President George Washington's first Cabinet; he was the Vice President.
Step-by-step explanation:
President George Washington's first Cabinet did not include John Adams as an original member. The first Cabinet consisted of four key positions and the individuals who held them were: Thomas Jefferson as Secretary of State, Alexander Hamilton as Secretary of the Treasury, Henry Knox as Secretary of War, and Edmund Randolph as Attorney General. John Adams was not a member of Washington's Cabinet because he was serving as the Vice President at the time.