Why did the French join the American revolution ?

Because France was Allies with America.

Explanation:

At the start of the war, France gave supplies (like gunpowder, clothing shoes etc) to the Continental Army. In 1778, France officially became allies (friends) with the US through the Treaty of Alliance. This made France become involved in the war.

explanation:

the muslim keep their culture pure by finding new value

in mcculloch v. maryland (1819) the supreme court ruled that congress had implied powers under the necessary and proper clause of article i, section 8 of the constitution to create the second bank of the united states and that the state of maryland lacked the power to tax the bank.

gibbons v. ogden, (1824), was a landmark decision in which the supreme court of the united states held that the power to regulate interstate commerce, granted to congress by the commerce clause of the united states constitution, encompassed the power to regulate navigation.