Robert Murray and his brother James migrated from Northern Ireland to Baltimore, MD pror to 1770. According to family tradition, the Murray brothers, who were Scots-Irish Presbyterian, had a quarrel on the boat with some Catholic Murrays. So they changed their surname on arival to Morrow. When Elizabeth Crawford Morrow visited Ireland in 1956, she asked about the names and learned that Murray was usually a Catholic surname while Morrow was likely to be Protestant.
The Murray surname appears on two of Robert's legal documents - the indenture for Sinking Valley lot #30 dated May 3, 1793 and his will probated April 6, 1810 (Huntingdon County, PA, Wills volume 1, page 171).
James Murray remained in Baltimore while his brother Robert pushed into the frontier around 1772. For a while he lived in Path Valley, located north of Fort Louden along PA route 75. In addition to clearing land and farming, he conducted a small store. While living in Path Valley, Robert married Rebecca. There is a question about Rebecca's last name being Cochoran or McNit. Their first child, Robert II was born in Path Valley in 1777. He was brought to Sinking Valley on horseback in his mother's arms when the couple moved "west" in 1780. Another son, James, was born in Sinking Valley in 1785. In Sinking Valley Manor, Robert and Rebecca settled their family on land surrounding what is known in 2009 as Tytoona Cave.
On July 22, 1806, James, still living in Old Town Baltimore, wrote at letter (original held by the Sinking Valley Family Tree Project) to his brother Robert in Sinking Valley. He addressed it to Mr. Robert Morrow and signed it, James Morrow.
By the time the 1812 Huntingdon County list of taxable landowners was compiled, Robert's sons Robert II and James were using the surname Morrow.