In what ways and with what motives USA was involved in the affairs of Latin America during the Second Half of the twentieth century?

It was thought that the economic aid provided by the USA will help Latin America solve the problems. Kennedy started Alliance for Progress which was aimed at giving billions of dollars to Latin America to initiated economic and political reforms. But the motives of the USA was to solve basic economic and political reform so that elections could be held. They wanted moderates to come into power as they would be able control the economy and keep the communist away from coming to power. The US compelled Latin America to buy US goods as a condition for the aid. This affected the local industries very badly and their growth was shunted.
The aid was cut short if the government unacceptable by the USA came into power. And the only way to resume the aid was to change the government. In this way USA influenced the political system by using economic control. Sometime USA used rebels by supplying them with weapons to overthrow the unacceptable government as it did in Guatemala in 1954.