Abraham Lincoln signed the Emancipation Proclamation. Whom did the
Proclamation declare free?

they required less loading and unloading

explanation:

the shipping container improved shipping because it cut down on unloading time by three weeks, eliminated wasted space, and allowed ships to carry.

“the battle of stalingrad is not a turning point necessarily in strategic terms, because a lot more has to be done before the soviets can be certain of defeating germany,” says renowned world war ii historian richard overy. the germans had fought nearly a thousand miles across the soviet union to get to stalingrad.

porter is writing economic history because he is focusing on the cost of developing vaccines.