A more thorough explanation:

The Corporation Act was a law passed in England in 1661 (13 Car. 2, St. 2, ch. 1) that made it illegal for anyone who did not take the Anglican sacrament and the oaths of supremacy and allegiance to hold public office.

For example, if someone did not follow the Anglican Church, they could not hold a government job. This law was in place for over 200 years until it was repealed by the Promissory Oaths Act of 1871.

The Corporation Act was a way for the government to control who held power and to ensure that those in power followed the official religion of England. It was a controversial law that discriminated against those who did not follow the Anglican Church.