Answer :

     Homestead Act provided an incentive for people living in the east to come out west and own a parcel of land if they stayed on it for five years. It was designed to bring more people out to unsettled land and people took the chance - they wanted land of their own and it was getting increasingly difficult to own land in the east as prices kept going up...
      Dawes Act designed to help Native Americans by surveying the land and distributing it out to them - it tried to keep friendly relations with Native Americans...
      Transcontinental Railroad connected the West with the East - it provided an opportunity for people to travel east to west safely - less chance of Indian raids and stuff that would make people reluctant to travel...
      These helped w/ the expansion of the U.S. because it joined all the lands from west to east together - it made the U.S. available for people to settle in. pass through, and visit...