He was a member of the Episcopal Church and the United States Democratic-Republican Party.
He attended West Nottingham Academy in Cecil County, Maryland and graduated from the College of New Jersey (later Princeton University) in 1769; he then studied law at the Middle Temple (one of the Inns of Court where English barristers are trained) in London, England. He returned to the United States in 1775 and practiced law in Dorchester County.
He served as a member of Maryland State House of Delegates from 1777 to 1780 and a member of the Maryland State Senate from 1780 to 1790. During that time he was chosen as a delegate to the Continental Congress from Maryland from 1778 to 1780 and from 1785 to 1786; during his service, he was a member of the committee that prepared the ordinance for the government of the Northwest Territory. He was elected to be one of the first two Senators from Maryland, serving 1789 till his resignation on December 10, 1797, to take the Governorship. He received 2 electoral votes for President of the United States in the 1796 election. He served as Governor of Maryland from 1797 to 1798. He died in Dorchester County, Md. at the same estate, named "Weston," where he had been born.