The Americans thought that Napoleon might withdraw the offer preventing the United States from acquiring New Orleans at any time, <span>, so they agreed and signed the Louisiana Purchase Treaty on April 30, 1803. On July 4, 1803, the treaty reached Washington, D.C..</span>
The Zimmerman telegraph allowed communication across farther distances, making a world war more feasible. This gave a certain amount of confidence and the U.S. joined the war.
His name was Albert Einstein that’s the answer
