What mistake by colonel george custer led to his defeat by chiefs sitting bull and crazy horse at the battle of little bighorn?

The correct answer is Custer and his force arrived ahead of the main U.S. force.

General George Custer's and his 7th Cavalry were defeated at the battle of the Little Bighorn, Montana, by the Sioux and Cheyenne Indians. Chief Sitting Bull and Crazy Horse commanded the Indian troops.

General Custer and his 264 men's were needed reinforcement in the battle but supporting U.S. columns failed to arrive on time and rescue them.

"a government in which power is divided between state and national levels". federalism is a system of government in which entities such and state and province, share power with the national government.

2686-2181 bce-- "egyptian civilization developed along the nile river in large part because the river’s annual flooding ensured reliable, rich soil for growing crops."

1069-664 bce-- "ancient egyptians developed wide-reaching trade networks along the nile, in the red sea, and in the near east."