Laurens A. Grannis was born on March 27, 1803, in Claremont, New Hampshire, to Timothy Grannis and Phebe Rice. He married Mary Johnson in Claremont on October 20, 1831, but she died four years later. He married Martha Cola in June 1836, and they had at least six children together: Edward, born on November 30, 1838; Mary, born around 1839; Timothy, born around 1841; John, born around 1848; Harriet, born around 1851; and Margaret, born around 1853. Grannis owned $2,400 in real estate in 1850. A decade later, he was working as a farmer, and he owned $3,000 in real estate and $1,000 in personal property. He moved to Guildhall, Vermont, sometime in the 1860s, and by 1870, he owned $5,000 in real estate and $1,000 in personal property. He remained in Guildhall for the rest of his life, passing away on October 30, 1896, at the age of 93.