The transcontinental railroad united the nation through trade
Yes, it is a requirement for all state and federal officials. They must take an oath to support the constitution.
Black identity and cultures
Communism
For example, land was owned by the state in the Soviet Union.
The main diplomatic challenge facing President James Monroe in 1820 was "<span>d. responding to the revolt of Spain’s Latin American colonies," since this presented security challenges for the US. </span>