The rider attached to the Indian Appropriations Act of 1889 gave __________ the right to __________ the Unassigned Lands for settlement.

The rider to the Indian Appropriations Act of 1889 authorized the president to open the Unassigned Lands for settlement. President Benjamin Harrison issued the proclamation that opened the area, leading to the Land Run of 1889. Therefore, the correct choice is “the president . . . open.”

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