Not a historian but I have done a lot of research on the slave trade and the timeline mainly during post-abolishment.

Immediately afterward it does seem strange to imagine what a former slave could do. It's not too strange however if we remember that free Blacks did exist at the time. Free Men as well as Black, White and Native-American Abolitionists would have helped recently freed slaves start their new lives. This wasn't always the case though since the South still had a business to run. Basically, many slave owners still needed the man-power required to run their plantations after the war. They essentially just re-instated slavery in a "legal" way using well-crafted language, loop holes, surrounding support, and power. Sharecropping was the closest thing to slavery that became popular after the Civil War. Another thing that happened almost immediately were the "Black Codes". These were actually laws that severely restricted freedoms for blacks and basically kept them in worse off conditions(living, education, employment) than other races in the country.

After the Black Codes of the 1800's came the Jim Crow laws of the 1900's which were similar. As you get into the turn of the century however, you COULD have made a somewhat decent life for yourself in entertainment. You'd still experience racism(segregation, disenfranchisement and other institutional racism) but at least in the 1910's and 1920's you could possibly do well as a Jazz musician(Louie Armstrong, Duke Ellington, Cab Calloway). But make no mistake there were still many many lynchings and severe hate crimes at this time including the Atlanta riots of 1906 and the Tusla Race Riot of 1921. The Ku Klux Klan was very strong at this time also. Eventually many southern blacks not only grew tired of the overt, dangerous racism but also wanted to find better jobs, kicking off the Great Migration. Millions of blacks moved into northern cities that were experiencing an industrial boom(Chicago/NY/Detroit)from roughly 1910's through the 1950's. They still faced discrimination of course for not only being black but for "coming out of nowhere" so to speak.

Another thing to remember is that besides blatantly racist laws existing there were also pseudo-scientific books being written about how blacks(Negro/Negroid) were genetically inferior to Whites in every way. And to answer your specific question about buying houses and starting communities, they did sometimes. Understand, though, there was so much unfair discrimination built into the legal systems that getting a good education followed by a good job and creating a community of people like that made up of solely black residents was practically impossible. So rare was this that when it did happen it was destroyed by extreme racists i.e. Black Wall Street//Greenwood, Tulsa.

TL:DR - Although not physically enslaved after the Civil War, African-Americans were restrained to such an extent in everyday life that the word "slavery" could almost accurately apply to their lives.

Other source

Edit: I didn't mention the World Wars because I know they teach that in school. I tried to focus on the times right after the Civil War and before Civil Rights(1960's).

Edit 2: Linked my 5 sources. .edu, .gov, and .org except for history.com