William Allen was born on August 5, 1704 in Philadelphia, Pennsylvania, United States. He was a member of the Allen family of Philadelphia, Presbyterians from Dungannon, Ireland, who were prominent in that Scotch-Irish group which brought Pennsylvania into the national manner of thinking in time for the American Revolution.
Allen secured at London a legal training valuable throughout his future life.
In 1727 Allen entered the Philadelphia Council and for nearly fifty years his influence in political affairs is easily followed.
First came his leadership of Philadelphia when it petitioned the Assembly in 1729 to be allowed to erect a "State House. " The legislature, guided by Allen and Hamilton as trustees of the purchasing and building funds, established its first permanent home at Philadelphia, in October 1735, instead of at Chester, as the Quaker Party, to be distinguished from the religious Society of Friends, had desired. For the rapid completion of this future "Independence Hall" despite labor troubles, Allen advanced considerable money from his private purse, some of which was not repaid until 1761. Meanwhile Allen's influence extended. He was member of the Assembly 1731-1739, was elected Grand Master of Freemasons in 1732, and became mayor of Philadelphia in 1735. Chosen recorder of the city in 1741, he joined Franklin in defending the western frontier and in advancing provincial self-government, especially during the terms of his brother-in-law, Governor James Hamilton, 1748-1754 and 1759-1763. These activities, his initial aid to the College of Philadelphia, and his furtherance of many charities mark Allen's breadth of character. His reputation when justice of various lower courts 1737-1750 and as chief justice of the province 1750-74 proves his legal ability, although the texts of few decisions have been preserved. His position in the American Philosophical Society and upon the board of trustees of the University of Pennsylvania shows his literary interests. Allen's value to province and to country was demonstrated when he recommended Franklin for deputy postmaster-general of America (1751), and served on the Maryland-Pennsylvania boundary commission (1750-1751) to adjust the dispute between so-called "Penn pertinacity and Baltimore pugnacity. "
In 1765, being owner of a large estate in Northampton County, Pennsylvania, he laid out the town of Northampton, afterward named Allentown. Allen felt keenly the grievances of America against Great Britain. When in England in 1763, he obtained a postponement of the sugar duties, and later, in 1766, joined Franklin in securing a repeal of the Stamp Act. But for the next decade "the great giant, " as he was described, remained an advocate of compromise when wiser statesmen were realizing the necessity of effective colonial union. A member of the Proprietary party in 1774, he could not follow Franklin into American nationalism; thus, when his plan for reconciliation outlined in The American Crisis (1774) failed, his active service for Pennsylvania ended and he resigned his judicial position. When the Constitution of 1776 was adopted, Allen retired to England to await a reconsideration.
He died on September 6, 1780, after revisiting Philadelphia in 1779 and freeing his slaves by a codicil to his will dated December 1 of that year. Later opinion has recognized the difficulties of Allen's position and judged more kindly than did his contemporaries in 1776 this promoter of Pennsylvania's welfare during sixty years of loyal service.
Allen was a Loyalist. He agreed that the colonies should seek to redress their grievances with British Parliament through constitutional means, and he disapproved of the movement toward independence.
Allen was a Freemason.
On February 16, 1733 (or 1734) he married Margaret, the daughter of Speaker Andrew Hamilton.
