I just discovered this forum a moment ago by chance and will toss out my line. So far, have never connected to other Allansons outside my direct line who are kin somehow, but always hoping.
My 7th great-grandfather was THOMAS ALLANSON (also ALLISON), (1639-1681), Lord of Christian Temple Manor, a Gentleman of London, England and Charles County, Maryland. Thomas immiagrated to Maryland in 1658, returned to London to handle business affairs and wed Mary Roberts in 1662.
That 1662 marriage record was the first known instance of the ALLISON spelling of the surname. By the time of his grandson, also THOMAS, the ALLANSON spelling was lost forever in place of ALLISON.
Today this family is quite large in America. Thomas's descendants are bound together in the National Allison (Allanson) Family Association, and gather each October for a weekend long reunion, the National Allison Family Reunion which draws hundreds of cousins from up to 30 or more states to western NC where the majority of Thomas' known descendants are concentrated.
Would love to find more of the family in America, plus family left behind in England. Yours, Michael Allison, President National Allison (Allanson) Family Association