Which political party felt that the "missouri question" violated the principles of the northwest ordinance?

Congress - In the year 1820, the Missouri Compromise was passed, which declared Missouri as a slave state and Maine as a free state. This was intended as a measure to ease the tension between slave and free states, so that there was a good balance between the two kinds of states. However, the norther states were angered as they believed it was in conflict with the norther ordinance.