After Charles II's father, Charles I, was executed during the English Civil War, England became a republic for a few years under the leadership (and widely known as a dictatorship) of Oliver Cromwell. This harsh rule lasted about 7 years, and, after Cromwell died (and his son failed at taking his place), political instability led to the restoration of the monarchy, with Charles II taking the throne. He was then known as the "Merry Monarch" because 1) of the relief of the dictatorship of Cromwell being over and 2) he was willing to consent to Parliament's wishes in fear of another revolution.
One of the main ways in which changes to the railroad helped American industries to grow is that the expansion of the rail system led to increased migration to the west, which led to more farming and agricultural output. Another would be that it led to settlements that ultimately led to business that were able to conduct business over state lines with great ease.
The Indian Removal Act was signed by Andrew Jackson and it was a law that was supposed to call for the "voluntary" removal of Indians from their land. The United States wanted to expand and use their land, and ended up forcefully removing them and resulted in the removal of most Indians from the states altogether. Hope this helps! :)