What were two
obstacles the US faced before they
could build a canal?

The U.S. design overcame both the flooding and excavation problems. Diseases of yellow fever and malaria were dangerous obstacles that had already defeated French efforts to construct a panama canal in the 1880s. Many deaths and hospitalized workers had caused the French to give up on their project.

Explanation:

the 22nd united states congress

b.provides a written record of the transaction