1890 killing of Native Americans by U.S. troops; symbol of frontier conflict.

• A. Panama Canal Zone
• B. U.S.S. Maine
• C. Fourteen Points
• D. Wounded Knee Massacre

Answer: (D)

The main idea is that the Wounded Knee Massacre embodies the violent end of the American frontier and the suppression of Native American resistance. In December 1890, U.S. troops opened fire on Lakota people at Wounded Knee Creek in South Dakota, killing hundreds, including women and children. This brutal clash came at the tail end of a long arc of frontier wars and followed federal efforts to force Indigenous peoples onto reservations and assimilate them. The massacre is seen as a powerful symbol of how the United States used military force to constrain Native sovereignty and finish the era of westward expansion, marking the closing chapter of the frontier period. The other options don’t fit this theme: the Panama Canal Zone is about securing a canal route in Central America, the U.S.S. Maine is linked to the Spanish-American War, and the Fourteen Points relate to World War I peace plans.