Why is it important for historians to corroborate information found in a source?

One of the main problems with the indian reservation system was that government agents took land from settlers to give to american indians. dealt dishonestly with american indian families. did not understand the power structure of american indian tribes. gave land to settlers who removed american indians.

From the soviet point of view, which reagan policy most threatened to create a new arms race? a. strategic defense initiative b. u.s. support for israel c. aid to the anti-soviet rebels in afghanistan d. iran-contra scandal

Explain how zollverein, a tariff agreement, to unite the german states.