What became critical to protecting what blacks were achieving?

The 13th Amendment, which was ratified in 1865, abolished slavery. Three years later, the 14th Amendment provided blacks with citizenship and equal protection under the law. And in 1870, the 15th Amendment gave black American males the right to vote.

Explanation:

here you go hope it heps "horace mann"

b. major john c. frémont led a rebellion called the bear flag revolt.

explanation:

during the bear flag revolt, from june to july 1846, a small group of american settlers in california rebelled against the mexican government and proclaimed california an independent republic. the republic was short-lived because soon after the bear flag was raised, the u.s. military began occupying california, which went on to join the union in 1850. the bear flag became the official state flag in 1911.