Which preposition to use with unbiased

by Occurrences 4%

Fanny Kemble's Journal of a Residence on a Georgian Plantation, kept by her in the very year of Douglass's escape from bondage, but not published until 1863, too late to contribute anything to the downfall of slavery, is a singularly clear revelation of plantation life from the standpoint of an outsider entirely unbiased by American prejudice.

in Occurrences 1%

That the committee might be unbiased in their judgment, they were required to examine and decide upon the books without knowing the names of the writers.

on Occurrences 1%

Most of the good weeklies, certainly, speak the truth as they see it; they are, in fact, a very creditable section of our press; but the idea of the Fact was to be absolutely unbiased on each issue that turned up by anything it had ever thought before.

Which preposition to use with  unbiased