In the ten years following the civil war, a large numbers of former slaves earned a living by becoming
1. conductors on the underground railroad
2. workers in northern factories
3. sharecroppers on southern farms
4. gold miners in california

Kennedy singles out one group of countries that the united states will defend against any attacker what countries are they

In ohio in 1872, the cleveland massacre was a violent labor dispute at standard oil refineries in cleveland. a takeover by standard oil of the refineries in cleveland. an attempt to stop standard oil from becoming a monopoly. a failed attempt by standard oil to take over other refineries.

Overpopulation puts severe stress on the environment because .