Background
Gilman was born in 1833 in Gilmanton, New Hampshire to Charles Gilman and Eliza Gilman (née Page).
Gilman was born in 1833 in Gilmanton, New Hampshire to Charles Gilman and Eliza Gilman (née Page).
He attended school at Gilmanton Academy and later in East Andover, New Hampshire.
The Gilman family was a well established one in New England with roots dating back to the 1630s. After a brief career teaching in several different New Hampshire towns he relocated to Sauk Rapids, Minnesota in 1855. Gilman quickly became involved in local politics and became register of deeds and county auditor for Benton County, Minnesota.
In 1861 he was named the head of the General Land Office in Saint Cloud, Minnesota and relocated there.
He was later reappointed to the same office in 1866 and again in 1869. During this time Gilman also explored the timber and mining industries, pursuing interests in Minnesota as well as Ontario and further west.
In 1867 he was elected to the Minnesota Senate, serving until 1871. He was later elected to the Minnesota House in 1875 and served until 1880 (including as Speaker of the Minnesota House from 1878 to 1879).
During both terms Gilman was heavily involved in legislation surrounding railroads and supported the development of the Great Northern Railway (United States).
After serving in the legislature he became Lieutenant Governor under Governors John South. Pillsbury and Lucius Hubbard from January 10, 1880 to January 4, 1887. He unsuccessfully ran for the Republican nomination for governor in 1886 and 1888. From 1894 to 1899 he was the Minnesota State Librarian.
Gilman later served one more term in the House, from 1915 to 1917.
He died on June 7, 1927 in Saint Cloud, Minnesota. He is buried in Trinity Lutheran Cemetery in Sauk Rapids, Minnesota.