How did people do there laundry before automatic washing machines?

By hand with a washboard & washtub.

Washing requires agitation and something to help break down water's surface tension, usually soap.

Many cultures continue to do laundry by beating the clothing on rocks along the river. Placing them in large pots of boiling water and stirring was common in pioneer times. A number of plants were determined to have soap properties and would be mixed in.