Joseph Rollin Alger was born around 1833 in New York. He married a woman named Harriet around 1857, and they had at least three children: Fanny, born around 1858; Rollin, born around 1859; and Carrie, born around 1865. They lived in Boston, New York, and Algar worked as a farmer. By 1860, he owned $200 of personal property. A decade later, he owned $6,000 of real estate and $500 of personal property. He remained in Boston until at least 1910, and he died in 1918.