Why did american indians who lived in dry areas make knives from flint rather than slate?

Which term best describes the progressive era

Kennedy singles out one group of countries that the united states will defend against any attacker what countries are they

Which action by the us war department angered chief red cloud to the point that he refused to sign the treaty of fort laramie ? a) the killing of buffalo by the united states troops b) the appointment of troops to the powder river basin c) the burning of parts of the powder river basin d) the murder of chief red cloud’s wife