Why were railroad companies in a hurry to complete many miles of track-laying in the mid 1800s?

What best explains why the us government placed restrictions on asian immigration through angel island? many americans did not believe in assimilation. many americans did not approve of the gentleman’s agreement. many americans held nativist or racist views. many americans feared a loss of educational opportunities.

How do conflict minerals, and in particular, conflict coltan get their name? what groups benefited from the trade in conflict minerals? what group were hurt by it?

How were castas paintings used to stabilize a society?