Helen hunt jackson's a century of dishonor is a primary source from 1881 showing that americans protested the treatment of american indians in the last indian wars. jackson's work is important to understand because:

It changed the attitude of white Americans toward Native Americans.

Explanation:

Helen Hunt Jackson was born in Massachusetts, American known as a writer and poet who is famously known for her work  A Century of Dishonor in 1881 and became an activist on behalf of Native Indians treatments by the United States government. By the coming of this book, it was well-received and it affected White American attitudes toward Indians later on and also the government appointed a commission to look into Indian Ponca people.

disease was the number one killer of native peoples. they had had little exposure to the diseases of europe. this led to some villages being almost completely wiped out and some tribes destroyed.

the triple alliance. germany and austria-hungary were already allies by 1879 when, worried about a threat from russia, they formed the dual alliance. italy joined the group in 1882. there was a concern about a possible attack from france and the alliance needed powerful friends to defend it.