The name of the ice age land bridge between Russia and North American Continent

The Bering land bridge is a postulated route of human migration to the Americas from Asia about 20,000 years ago.

Explanation:

An open corridor through the ice-covered North American Arctic was too barren to support human migrations before around 12,600 BP.

the labor movement in the united states grew out of the need to protect the common interest of workers

for those in the industrial sector organized labor unions fought for better wages reasonable hours and safer working conditions

  in the 19th century trade unionism was mainly a movement of skilled workers.

hope this

might be agreeing to participate ethically with other european nations in the slave trade

or notifying other european nations when taking possession   of african territories