Which caused the failure of the fort laramie treaty that promised to protect native american lands “as long as the grass shall grow”?

The government broke treaties pure and simple. They allowed settlers to cross the Black Hills and seek gold. The Sioux considered the Black Hills scared and the plains tribes were often attacked by troops. Read Black Elk Speaks about an attack he experienced. In 1861 the Dakota Sioux were rounded up by the military after an attack on a settlers family. They took over 2,000 men, women, and children to Ft. Laramie. The government was going to hang 300 Dakota Sioux men, but Lincoln stopped it. Instead they hung 10 and this is the largest mass hanging in United States history, but no history book has it in it. Over and over treaties were broken, lands taken, and the Native Americans moved off ancestral lands.

I hope this helps!!!

She was one of the world's first female heads of state.