What provide for the common defense mean

This phrase means that the protection of the United States. its citizens, and property, is the responsibility of Federal Government, and not of individual states or of the insular areas under the jurisdiction of the United States

the option which was not a function of missionaries in the northwest was the first one - they established posts for trading furs and other goods.

missionaries were sent around the world to spread religion and their knowledge and others - they were not merchants who sold furs and other goods.