The case of Marbury v. Madison determined the power that the judicial branch of the government can have to limit the power of the legislative branch of the government.
Prior to the case, the congress can basically pass any laws that they want without any repercussion.
The case granted the Supreme court with the power of judicial review. This enable the supreme court to examine every laws proposed by Congress before its passed. The supreme court can rejected the proposal and prevented it from becoming actual law if it violated any part of the constitutions.
