Final answer:
Kerber likely changed the location of his work sites to those situated on Oneida Indian Nation territory due to the federal government disregarding treaties with Native Americans when they interfered with non-native interests such as land speculation or resource extraction.
Step-by-step explanation:
The question relates to the alterations made by the federal government in the location of lands occupied by Native American tribes and how individuals like Kerber had to adapt to these changes. This shift in land locations often occurred because federal treaties with Native American tribes were frequently disregarded when they became inconvenient for reasons such as land speculations, agricultural purposes, or the discovery of valuable resources on these lands.
Historical figures such as Helen Hunt Jackson highlighted the injustices perpetrated against Native Americans, through works like A Century of Dishonor, revealing that the federal government often chose convenience over justice. This led to the forcible seizure of native lands and violated the very treaties the government had initially agreed upon, significantly impacting the Native American tribes and their territorial sovereignty.
These actions, often justified by the growth of White settlement into the western United States and the desire for resources or land by non-native populations, resulted in tribes being alienated from their own lands and having to relocate. Kerber, likely a figure engaged in historical or cultural work, would have had to adjust his sites of interest to those now situated within the territory of the Oneida Indian Nation as a direct consequence of these historical actions.