Which country controlled the highlighted nations?
the united states
the soviet union
germany
great britain

The correct option is "the soviet union"
the soviet union, officially called the union of soviet socialist republics, was a marxist-leninist republic that existed in eurasia between 1922 and 1991. although formally it constituted a federation of 15 republics, its political and economic system was de facto strongly centralist, with a single party political system dominated by the communist party until 1990.

The transcontinental railroad provided a means of fast transportation. it cut a 6 month trip into 6 days, created jobs for many people and encouraged immigration. the homestead act played a huge role in western expansion; it allowed settlers to begin a fresh start, and gave them land in exchange for their residence for up to five years and a small fee.