What did u. s. government do in the 1860s to encourage settlers to develop the great plains

Does the threat of global warming require international cooperation? why or why not?

What events caused the united states to intervene in southwest asia?

What can you learn about precipitation levels in south america from this map? brazil is experiencing a drought.it rains more in higher altitudes.peru received the highest level of rain.venezuela got less than 25 cm of rain.