David Dobson has extracted data about the 150,000 Scots who emigrated to America before the Revolutionary War from a wide variety of sources, including family and estate papers, testamentary and probate records, burgh muniments, sasine and deed registers, Sheriff's Court records, Court of Session and High Court of Judiciary records, port books, customs registers, contemporary diaries and journals, contemporary newspapers and magazines, professional and university records, Privy Council and colonial records, records of Episcopalian and Presbyterian churches, monumental inscription lists, and the 1774-75 Register of Emigrants.