Thomas M'Kean was born in 1734 in New London, Chester County, Pennsylvania. His father immigrated from Ireland, and Thomas as the second child. He received the "usual elementary instruction" and then became a classmate of George Read under the direction of Reverend Doctor Allison.
When Thomas completed his studies there, he began studying law in the office of David Finney in New Castle. He was so talented in the study of law that he was "employed as an assistant clerk of the Court of Common Pleas" a few months after he began his studies. He was admitted to the bar before he turned 21 and had authority to practice law in three counties in Delaware.
Thomas was so successful in his profession that he "attracted the attention of most of the leading men of the day." Without any idea or effort on his part, Thomas was appointed to be the deputy to the Attorney General of the Province and given responsibility to "prosecute all claims for the Crown in the county of Sussex." He was only 22 years old!
In 1757 Thomas was admitted to practice in the Supreme Court of Pennsylvania. About the same time he was elected to be clerk of the House of Assembly of Delaware but declined a second election.
Thomas and Caesar Rodney were appointed in 1762 to "revise and print the laws of the Province enacted during the ten preceding years." That same year Thomas was elected to represent New Castle in the General Assembly. This act clearly illustrated the confidence of the people in that district because Thomas had "expressed a desire not to be elected" and had been living in Philadelphia for six years. When Thomas "urgently" requested to be allowed to resign from the legislature, the people sent a committee to him to request that "he nominate seven proper men in the district for their representatives." He at first declined the request, but the "request was urgently repeated." After he received assurance that he would not offend anyone, he offered the names of seven men. Then men he named "were elected by large majorities."
Thomas was a delegate in 1765 to the "Stamp Act Congress" and served on a committee to prepare an "address to the British House of Commons." That same year he was appointed by the governor to be notary public for the "lower counties on the Delaware." In rapid succession, he was appointed as Justice of the Peace, Judge of the Court of Common Pleas and Quarter Sessions, and of the Orphan Court. He was appointed Collector of the Customs in 1771 and Speaker of the Assembly of Delaware in 1772.
Thomas was very concerned about the "encroachments of British power upon American rights" and "zealously opposed" them. He ardently supported the recommendation to hold a General Congress and was elected to be a delegate to the Congress opening on September 5, 1774. He was very active in the Congress and continued to be a member of the Continental Congress until 1783 when the treaty of peace was ratified.
M'Kean firmly believed that there could be no reconciliation with Great Britain and "zealously" supported the movement to write a final Declaration of Independence. When the Declaration was submitted to the members of Congress for action, he voted for it and signed it.
Thomas was leading a regiment under the direction of General George Washington in New Jersey in September, 1776, when he was elected as a member of a convention assigned to write the Delaware State Constitution. He wrote that constitution, which was adopted with a unanimous vote.
M'Kean had the distinction of being claimed as a citizen by both Pennsylvania and Delaware, and he served both states faithfully. In 1777 he served as Chief Justice of Pennsylvania while at the same time serving as President of Delaware. He also served as Speaker of the Delaware Assembly and as a delegate to the Continental Congress. He became President of the Congress in 1781 but resigned in November with the thanks of Congress.
Thomas continued to serve both Pennsylvania and Delaware. He held the position of Chief Justice of Pennsylvania until 1799, a period of about twenty years, when he was elected Governor of that state. He was elected to that office for three consecutive terms and a total of nine years. At the 1807-08 session of the Pennsylvania Legislature, his opponents presented articles of impeachment for maladministration. It ended with a resolution that "Thomas M'Kean, the Governor of the Commonwealth, be impeached of high crimes and misdemeanors." Even though the charges were brought before the House, they were never acted upon because they were constantly being postponed.
Governor M'Kean performed his last public act when Great Britain threatened to attack Philadelphia during the War of 1812. He retired into private life. He passed away on June 24, 1817, in his eighty-fourth year of life.
Facts and quotes are from Lives of the Signers of the Declaration of Independence, pp. 141-145.