Code talkers transmitted messages over military telephone or radio communications nets using formally or informally developed codes built upon their native languages. The code talkers improved the speed of encryption and decryption of communications in front line operations during World War II
The transcontinential railroad brought more money to the railroad companies because more people had access to the railroads, therefor using them more, and money was brought in. Not 100% sure, but that is my guess
In the election of 1800, Jefferson and Burr tied.
The main issue is that second place got VP, instead of a ticket running together. So, a President would not have the choice of VP.