Later, together with the Native American chief Nemacolin, Cresap improved a Native American path to the Ohio Valley, and ultimately settled and became a large landowner near Cumberland, Maryland, where he was involved in further disputes near Brownsville, Pennsylvania, including in the French and Indian War and Lord Dunmore's War.
He initially settled at the mouth of the Susquehanna River on the Chesapeake, on the lower end of a floodplain called the Conejohela Valley, and built boats.
Cresap also traveled at least once to Virginia, for Virginia-based trader Claiborne also traded for furs in the lower Susquehanna area of Chesapeake Bay.
Upon returning to Maryland, Cresap secured a patent to operate a ferry over the Susquehanna at the head of tide-water from Lord Baltimore.
Cresap came to Conejohela Valley in March 1730, and built a block-house on the banks of the river three and one half miles below today's Wrightsville, near the site of Leber's Mill.
However, they had no one capable of holding the ground they had taken either from the Indians nor from the Pennsylvanians, who were determined to prevent Baltimore from gaining a foothold on this disputed area.
Cresap became a notorious figure in the Conejohela Flats area—the lower Susquehanna Valley in the area south of Wright's Ferry—where his actions (and those of his men) as an agent on behalf of Lord Baltimore made him a wanted criminal in Pennsylvania.
Because of the bloodshed during Cresap's War, King George II issued an edict forcing a settlement of the Maryland-Pennsylvania boundary dispute against the claims by Lord Baltimore.
While Pennsylvanians imprisoned Cresap, his wife and children lived with his cousin Daniel Lowe, who drove one of the German settlers from his home in Grist Valley (Kreutz Creek), near Codorus.
He patented about 2,000 acres (8.1 km2) of land in Maryland along Antietam Creek, where Cresap established a store and Indian trading post.
[3] Cresap then moved farther west to within two miles (3 km) of present-day Cumberland, Maryland, where he again embarked in the Indian trade.
Cresap founded what is now Oldtown, Maryland by building a trading post at the foot of the Amerindian trail over Wills Mountain (renamed Haystack now near Cresaptown).
[4] A decade later, George Washington and his troops would further improve the same road prior to Braddock's Military Expedition during the French and Indian War.
She mounted her horse, sounded a bugle, and rode rapidly to Cresap's fort, three miles (5 km) and a half down the river.
When the French and their allies attempted to seize the territory west of the Allegheny Mountains from the English, Cresap and his sons at their own expense raised two companies of volunteer soldiers.
The oldest son, Daniel Cresap, remained in Washington County, Maryland, and became a large landholder and a celebrated hunter as well as a farmer.
[6]: 603 By a second wife he had seven sons and three daughters: Daniel, Joseph, Van, Robert, James, Thomas, Elizabeth, Mary and Sarah.
In 1774 he employed several men and descended the Ohio River and was engaged in the business of erecting houses and clearing lands for the settlers.