How was President Johnson able to get the US involved in Vietnam?

What states were considered part of the antebellum south?

How are the republican and democratic presidential candidates chosen? a. they are nominated by their state governments. b. each is nominated by his or her respective party. c. each is chosen by the governor of his or her home state. d. they are chosen by the house of representatives.

The united states economy makes up how much of the worlds economy