The name Blalock or Blaylock appears to have originated from Scotland with the term 'Blayloc' which is a rare name recorded in Annan in 1801. It probably started from the Old English term blae lock, meaning livid or lead-colored hair, though it may have began from local Scotland sources. The earliest known Blalock was Thomas Blalock, born about 1560, probably in England, who was married to Thomasina Typlady. Their son was Thomas Blalock, born about 1599 in York Co., England, he emigrated to Accomac County, Virginia where he married his wife Rachel about 1627, and he lived there until his death about 1660. Their children included Thomas Blalock Jr., born about 1628 in Accomac Co., Virginia, Rachel, born about 1629, William, born about 1631 and John who was born about 1632. There is considerable confusion in various records about the descendants of these Blalock children, some records indicate that Thomas Blalock Jr. married Anne Christian Scott in 1668 in Virginia and their son John William Blalock was born in 1671 in Louisa County, Virginia, and he married Elizabeth Millington in 1698. Some records show a second wife named Mary Terrell, and other records list Mary as the only wife of John Blalock Sr. who was the father of John William Blalock, rather than Thomas Blalock Jr.
Nevertheless, Mary Terrell was directly descended from the famous Norman Conquest Knight, Sir Walter Tyrell, who accidentally (?) killed English King William II (William Rufus) with an arrow, while hunting in the forest, in 1100 A.D.
Some records for John Blalock and Mary Terrell list their children as John Blalock Jr., born about 1680 in New Kent County, Virginia, Mary Blalock, born about 1682 in Va., David Blalock, born about 1684, Lewis Blalock, born about 1686, Richard Blalcok, born about 1688 and Elizabeth Blalock, born about 1690, also in Virginia. The children of John Blalock and Elizabeth Millington were John Blalock III, born about 1702, Zacharidiah Blalock, born about 1705, Anne Blalock, born about 1708, Elizabeth Blalock, born about 1711, Millington Blalock, born about 1714, William Blalock, born about 1716, David Blalock, born about 1719 and Richard Blalock, born about 1722, he married Rachel Hardin in 1745. Elizabeth Millington's ancestors can be traced back to at least 1478 to Thomas Millington born at Holme On Spalding-Moor, Yorkshire, England. David Blalock, son of John William Blalock and Elizabeth Millington, married Anne, and their son, George Henry Blalock, was born about 1752 and married Patty Brewer, moved to Ohio where the children were born, including Meredith 'Meridy' Blalock, born in 1790, who married Mary Calhoon, and among their children were William Blalock, Meridith Blalock and Anna Blalock, born on September 15, 1819 in Ohio. She met her future husband, Francis Marion Spencer, in Porter County, Indiana, and they were married on September 21, 1837 there. They moved to Missouri, finally settling in Putnam County, Missouri, and had 9 children, including Sarah Jane Spencer. Threatened by neighbors who favored slavery for Missouri during the Civil War, Francis moved the family by ox wagon along the Oregon Trail in1864, to Walla Walla, Washington, and then to Benton County, Oregon. One daughter, Sarah Jane married John Parker Huffman in Benton County, Oregon on September 9, 1874.

Among other well known Blalocks in history is Nelson Gales Blalock, born in 1836, a well known physician and agriculturist, who at the time of his death in 1913, was recognized as the foremost citizen of the State of Washington. William McKess 'Keith' Blalock and his wife 'Sam' were both enlisted in the Federal Army (she in disguise) in 1862, while it was stationed in 'Eastern North Carolina and had very unusual adventures during the Civil War. Lake Blalock in North Carolina, near the site of the Battle of Cowpens, was named for an early pioneer. Jane Blalock is a well known golfer who won the Dinah Shore Tournament in 1972. Jolene Blalock is a young actress from San Diego who will be starring in the new Star Trek series "Enterprise" on TV as the Vulcan subcommander T'Pol. Hank Blalock is a promising rookie third baseman for the Texas Rangers Baseball team.