Here is a personal. account, a little confusing. It appeared as "Notes on Hugh Wallace" in Ancestry.

 In the 1955 DAR magazine, it says John Wallace came from Ireland with three brothers. William settled in Goshen, New York, James settled in Philadelphia, Hugh in South Carolina, and John in Carlisle Penn. After the birth of William's son and daughter, John went to Londonderry, Ireland and married ? Crawford. When his youngest child, Robert was 6 years old, in 1798 they returned to Cecil County, Maryland where John died in 1810.
Hugh's application for the French and Indian War says he was born in Pennsylvania. Also his daughter, Elizabeth lived to be 100 and stated that both her parents were born in Pennsylvania.

Dorothea Wallace Silbert, a descendant visited his grave. The stone is now unreadable but a Revolutionary War marker was in place also.