From online genealogy http://wc.rootsweb.ancestry.com/cgi-bin/igm.cgi?op=GET&db=rkinney14&id=I8919:
'John immigrated to America and settled in Calvert County, Maryland, in or about 1658. A few years later he moved to Anne Arundel Co. where he resided until his death, which occurred on or about October 18, 1707. The name of John Sellman 1st appears in the Maryland records in the early settlers list, vol 6, p63, land office, Annapolis. John Sellman was probably a youth of about 12 or 13 years of age when he arrived in Calvert County, Maryland. He entered the colony as a custom servant and seems to have been so employed for a term of ten of 12 years. At the end of that period he obtained his release, and, according to the practice of the time, probably received several articles of wearing apparel, a few farm tools, and some seed corn. He also received from the Lord proprietor two warrants, each for 50 acres of land.'