Historians seek to interpret historic sites, artifacts, written records, and verbal histories without adding their own what?

ideas of the historic background
theory they hope to prove
biases of interpretation
narrative of the course of events

The correct answer is - Biases of interpretation.  

In general, the historians are trying to avoid adding their biases of interpretation of the history. They try to focus on using as information only the sites, the artifacts, what has been written, the verbal history among the peoples, in order to give the most objective interpretation of the historical events.  

Unfortunately, there's also lot of historians that do tend to use their biases of interpretation of the history, often resulting in nationalistic ideals, tensions between nations and people, and even war if they are convincing enough.

the statment would be a easy nonviolent one

jim crow law, in u.s. history, any of the laws in which racial was enforced, in the south between the finish of reconstruction in 1877 and the start of the social liberties development during the 1950s.

jim crow was the name of a minstrel routine( jump jim crow) performed starting in 1828 by its creator, thomas dartmouth ("daddy") rice, and by numerous imitators, including on-screen character joseph jefferson.

the term came to be a defamatory sobriquet for african americans and an assignment for their segregated life. the segregation rule was stretched out to parks, graveyards, theaters, and eateries with an end goal to keep any contact among blacks and whites as equivalents.

it was classified on neighborhood and state levels and most broadly with the "separate yet equivalent" choice of the u.s. preeminent court in plessy v. ferguson (1896).