It allowed Missouri and then Maine (which also applied for statehood) to become states. A lot of states were on the edge on wether to admit or not allow a state that allows slavery into the states. In the end - both were admitted and became states. However, Missouri was left as a slave state and Maine was set as a free state.
Basically, by purchasing an indulgence, an individual could reduce the length and severity of punishment that heaven would require as payment for their sins, or so the church claimed. Buy an indulgence for a loved one, and they would go to heaven and not burn in hell.
The allies agreed on a "Europe First" strategy because only Germany had the ability to bomb Britain, fight U.S and British Navies, and B. Seriously threaten to defeat the soviet Union
The Allied than concluded that Germany is a serious long term Threat and should be taken care of as soon as possible
hope this helps