Jacob Cooke, son of John Cooke ….. During the French and Indian war he served as an ensign in Col. Elder’s ranging battalion, and commanded the first military company enrolled for the war for independence in Pennsylvania, “The Association of the Liberty Company in Lancaster County.” This company was organized in April, 1775, and portions of the command were in active service during the campaigns of 1776 and 1777. Col. Cooke filled the office of sub-lieutenant of Lancaster County, assisting in the organization of troops. He was justice of the peace many years, and served in the Assembly under the Constitution of 1776 from 1780 to 1785. He was an ardent patriot, a brave officer, and an influential citizen. He died at his residence near Round Top. He owned a large estate, especially in Northumberland County lands, and left at his death John, Mary, (married John Lukens Wallis) Sarah, (married Joseph Work) Elizabeth (married Charles Irwine) and Robert. The two latter resided on the Muncy farms. Col. William Cooke, of the Pennsylvania line, a gallant soldier of the Revolution, was a brother of Col. Jacob Cooke, and one of the administrators of his estate.
History of the Counties of Dauphin and Lebanon in the Commonwealth of Pennsylvania by William Henry Egle, M.D., M.A., published Everts & Peck, Philadelphia, PA, 1883