How did the country allow slavery to expand as the nation grew?

no

explanation:

not everyone in america is free. it is has always been a unequal society. and yet people come in swarms, in search of better lives. some are brought as children, unaware, unknowing. some arrive and just don’t leave. they build lives, pay taxes, raise families. some enter illegally, fleeing persecution in their home country.

there are many reasons why human beings are so attracted to america, despite its history of bitterness towards immigrants.

there are almost two million immigrants brought to the us when they were children. president donald trump and his collaborators are determined to rid the us of as many undocumented immigrants as they can, and stop others from coming because none of their ancestors were immigrants.

america has so many things and yet it lacks the one thing that humanity needs to fully thrive. and so this country will not be at peace in itself until it resolves the pain at the heart of slavery, attacking immigrants, and crumble the rights of those with less power.

answer: the time zones used to be whatever the local authority wanted them to be. one town might have 6am whenever the sun came up and another town had 6am 10 minutes later.  

the trains had a hard time when their orders said to be at a certain point at 6am.  

6am, but who's 6am.  

the railroads got together and set the time zones more or less along the longitude lines across the country.

explanation:

the option which was not a function of missionaries in the northwest was the first one - they established posts for trading furs and other goods.

missionaries were sent around the world to spread religion and their knowledge and others - they were not merchants who sold furs and other goods.