Frontiersman Michael Cresap (June 29, 1742-October 18, 1775) was born at Oldtown, Maryland. His father, an Indian trader, was the first settler at that site along the Potomac River, across from present Hampshire County. Cresap was married to Mary Whitehead in 1764 at Philadelphia. The following year, Cresap and his wife occupied a new stone house in Oldtown, which he had built, a structure that now houses the Michael Cresap Museum.

In the early 1770s, Cresap led Virginia frontiersmen in their opposition to Pennsylvania's assertion of authority in the area south and west of the Monongahela River. This action established him as a leader in the region. In 1774, hostilities were renewed between whites and Indians in the upper Ohio Valley. Cresap had begun to clear land near Wheeling, where he was chosen by frightened settlers to lead an armed band to the Shawnee villages in Ohio to take revenge for several attacks and murders of whites. The result was a series of Indian skirmishes, known as Cresap's War. The most despicable act of this engagement was the murder on April 30 of several Indians at Yellow Creek, including a brother and sister of the Mingo Chief Logan by a group of settlers led by Daniel Greathouse. Logan and others, including Thomas Jefferson in his Notes on Virginia, blamed Cresap for the murders, though Cresap was not present at the killings and later condemned them. Logan's campaign of revenge helped to bring on Dunmore's War, which culminated in the October 1774 Battle of Point Pleasant.

In June 1775, Cresap was elected captain of the First Company, Maryland Rifles, which endured a forced march to join the siege of Boston. He became seriously ill during the march and ensuing battle and started home to recuperate, but he died in New York City.