What does the “iron curtain” refer to?
a the independent nations under the control of a more powerful nation
b the border between the soviet satellite states and western europe
c the promise to nations struggling against communist movements
d the 46-year rivalry between the united states and the soviet union

in the 1800s, locomotives powered by steam made transportation faster and cheaper. the resulting rapid growth of railroads led to the connection of the atlantic and pacific railroad in oklahoma city in 1897.

in the last years of the century, the improvement of steam-based engines the expansion and growth of railroads. this growth increased when the companies started to build and expand, such as the atlantic and pacific railroad, which connected new mexico with california, and missouri with oklahoma. many of these new networks were built in oklahoma, and these changes transportation henceforward.

the correct answer is a: slaves from other colonies ran away to georgia.