Final answer:
Andrew Jackson was the person most responsible for the U.S. government's policy toward Indigenous peoples in the late 1800s, notably through the Indian Removal Act of 1830 which caused significant suffering and displacement.
Step-by-step explanation:
The most responsible person for the U.S. government's policy toward Indigenous peoples in the late 1800s is often seen as Andrew Jackson. He was a major proponent of the Indian Removal Act of 1830, which led to massive relocation and suffering of Indigenous communities, known infamously as the Trail of Tears. Although other presidents like Ulysses S. Grant sought to encourage humane treatment and later assimilation of Native Americans, it was Jackson's policies that set the precedent for the harsh and aggressive treatment of Indigenous populations in the United States during this era.