I believe your William may be part of our family line.
My great, great grandfather, John Forson (1829-1872)was a stone mason and eventually settled in Cold Spring, N.Y.His wife, Mary Orkney Elis Smeaton (1831-1914) was born in the Orkney Islands, Scotland.They had several children Elizabeth R. (1853-1881), John (1863-1959), Alice (1868-1946), James Smeaton (1871-1965, my great grandfather), William, Isabella, and Mary.(I do not have exact birth dates for William, Isabella and Mary as of yet.)
We kown William lived in Brooklyn.My father recalls his grandfather and great uncle who owned a general store together in Garrison, N.Y. talking about their brother who lived in Brooklyn.My great, great grandmother's obituary also states "surviving children are three sons, John and James of Garrison, and William of Brooklyn, N. Y. and three daughters, Mary is Mrs. Howard Robinson of Garrison, Isabella married Gardner Irving, their home is at Hasbrouck Heights, N. J., Alice married Herbert Heffner, they live in New York City."
Unfortunately, I do not know where William was born.I know the Forsons were originally from VA and Georgia areas before moving up to New York state; however, we do not know where Mary O. E. Smeaton and John Forson met, or anywhere they may have lived prior to Cold Spring, N.Y. (like possibly Hastings).
Would also like to find more about the Forson branch in Brooklyn.