Thomas Mifflin was a great American politician and a merchant from Philadelphia, Pennsylvania. Mifflin was born in the 10th day of January in the year 1744 and lived until the 20th of January 1800. During the period of the American Revolution, he became a respected major general of the Continental Army, an associate of the Provincial Assembly of Pennsylvania, a Pennsylvanian Continental Congressman, the U.S. Congress's fifth President under the Confederation Articles and a Constitutional Convention delegate in the year 1787. He then became the speaker of the House of Representatives of Pennsylvania, President of its Supreme Executive Council. He also served as Pennsylvania's first governor.

Thomas Mifflin was the son of Elizabeth Bagnali and John Mifflin. He had finished his degree studies in the College of Philadelphia which is now known as the University of Pennsylvania. After that, he decided to venture with William Biddle's mercantile business. In March 4, 1765 which was his return from a European trip, he was able to establish a mercantile business partnership along with George Mifflin, his brother, as well with Sarah Morris, his cousin. He became one of the American Philosophical Society's members.

Thomas Mifflin took time away from the Continental Congress during the early part of the Revolutionary War in order to lend his services to the Continental Army. Due to his great involvement with the said military force, he was expelled from his membership of the Religious Society of Friends even though he belonged to a family known to have been Quakers for a length of four generations. On the 14th day of August 1775, he was honoured to become a major, an aide-de-camp of George Washington, as well as the very first Quartermaster General of the army thereafter. Though he excelled in that position, he still preferred to be located on the front lines. Through his combat leadership, Mifflin was promoted from colonel to the prestigious rank of brigadier general. There was a time that Mifflin asked to have himself relieved as Quartermaster General, but then had to go on with his duties due to the difficulties that the Congress had in finding a fit replacement.

Thomas Mifflin served on the Congressional Board of War which was created after a debate that was conducted in Congress with regards to whether states should have their individual forces maintained or national armies would be more efficient. He was able to make his decision of rejoining the army. However, he was a little less active with his role and criticism about his quartermaster general service followed. Accusations about embezzlement arose at some point after that, but fortunately, Mifflin was proven innocent. He resigned from his commission after that time, but Congress continued to seek his advice even after his official resignation.

Thomas Mifflin was able to serve two terms within Pennsylvania's Continental Congress. The 20th day of December 1790 marked Thomas Mifflin's Presidency and first governance. He finally returned to the legislature when Thomas McKean had succeeded him on the 17th day of December in the year 1799. Mifflin passed away one month after that.