One purpose of the Black codes was to find workers to replace enslaved people.
After the North (Union) won the Civil War, Southern states sought to still keep Black Americans at a lesser status than Whites and because they had just lost their labor force - enslaved people - they wanted a way to get them back.
Black Codes were so restrictive on Black people that one could easily see that they were passed simply to get Black Americans back on the plantations doing hard labor because some of the penalties involved arresting Africa Americans and making them work for free.
A muckraker is a journalist who devotes their work to uncovering topics that might be overlooked or ignored by the powers that be. That said, a muckraker is D a writer who exposes unsafe working conditions.
It improved communication a lot not and enabled people to save money on transportation (its easier to call someone than write a letter and make someone on a horse ride for miles) not sure about the effects on power though.
