Mansur was born in
Pembroke, New Hampshire, the son of Aaron Mansur and Rebecca Warren. He studied at
Phillips Academy and graduated from
Harvard College and Law School in 1831.[2][7][8] He later settled in
Fitchburg, Massachusetts, where he owned a textile mill, and served as director in two local companies and as Postmaster (1859- Sept. 1861).[4] He married Anna Stewart Fitzpatrick,[9] an Irish immigrant,[10] and they had five children, of whom three survived to adulthood.
In addition to his terms in the state legislature, Mansur also held local office, ran unsuccessfully for US Congress in 1842,[11] and ran unsuccessfully for statewide office on the Democratic ticket in 1860. Mansur's eulogy of
Daniel Webster (who died in 1852) won him note.[12]
In the early 1860s Mansur moved to Michigan, and in November 1862 bought the Kalamazoo Gazette.[13][14] He sold the paper some time after April 1865.[15]
^The April 21, 1865 edition of the Gazette was the last available issue bearing Mansur's name as editor and proprietor. The actual date on which he sold the paper is not certain.
^Some sources have his place of death as
Hyde Park. However a contemporary note from a Samuel A. Green (15 Feb. 1892) on file at the Harvard University Archives indicates that it was actually Milton.