It does stem back to slavery broadly where black communities were housed away from white communities and largely in most cities those divides are still there, there has been very little that has been done which has resulted in significant integration. There are essentially black areas of the city (generally downtown ghetto areas) and then there are white areas. Its totally different to what you see in Australia, where 1 neighbour could be black, another chinese etc for example.
The main issue IMO is education. Education generally leads to multiple things, better qualifications, better jobs, higher disposal income etc. The problem is that education funding appears to be designed to continue to favour rich white areas, and conversely penalise those that live in poor areas, as roughly 50% of the funding of schools comes from local government property taxes, clearly the higher the value of properties in an area, the higher the taxes raised and the more money invested into schools.
The attached report shows the differences between black and white students (and several other ethnicities too including Asian who do very well much like in Australia). One of the keys of this though is the level of kids in poverty (31% of black children live in poverty, only 10% of Asian and white children). Massive difference and one of the key components of improved education, is funding for schools, but also more parents being financially stable. Its not uncommon in the US for people to have 2 or 3 jobs. I haven't seen the stats but I think its likely that those with more than 1 job in the US would be far higher than in Australia.
By continuing their funding method for schools (which is very different in Australia) they continue to under resource poor community schools and invest more in richer school areas. In Australia the Schooling Resource Standard is designed to maintain education standards across the board regardless of economic propserity of the area where the school is located, so we get a much more consistent teaching standard throughout Australia. Its not uncommon in the US for poorer schools to ignore certain subjects as they simply cannot fund that department so kids essentially go without.
Lowering the funding gap for schools in the US should be a priority focus but it will take a big swing in philosophy but the current method essentially condemns poorer communities to poorer education standards and it is therefore very difficult to break out of this cycle and hence why very little has occurred to change areas from being dominated by 1 race.
A lot of the BLM movement is focused around police brutality and I do see both sides to these stories. There have clearly been cases where police have overstepped the mark and this has resulted in loss of life, but due to poverty levels, gang culture and the availability of guns, its an incredibly difficult place to police. There are significantly higher proportions of black americans killed by firearms than any other ethnicity, and its not even close. See below. Its also consistent across almost every state in the US but highest in those that we've probably heard on the news, Illinois (Chicago), Indiana (Indianapolis), Michigan (Detroit), Missouri (St Louis) to name just a few. The higher level of gun crime in these areas, will almost certainly increase the jumpiness of cops, but thats not to deny there is likely racism that has some impact, but when you have more chance of being shot by a black american than a white american then of course you would be heavier handed when that occurs. It feels alien to us in Australia to hear of police killing people as it happens so infrequently, but the same goes the other way, there are very few killings of police which again cannot be said for the US. Look at the headline news that was made when those 4 cops were killed last year in Melbourne when the truck hit them on the West Gate Freeway. Headline news for days, outpouring of grief, unfortunately killings of and by police in the US seem to happen daily leading to the population essentially becoming indoctrinated to these occurrences, its basically daily life, similar to the way they now see school shootings. There have been clear distinctions drawn up of deaths by police by race which shows an inherrent trend towards more black deaths, but its not widely distributed to show those police shootings in line with gun crime in those areas, it will almost certainly show a similar trend, indicating that the biggest issue is not necessarily underlying police racism but the income standards across race divides (ie. poverty levels which lead people to become desperate and leads to other sources of income and growth in petty crime, gang culture etc).
I find one way to look at the "lawlessness" of some parts of the US, is that when visiting places in the US, you are advised not to go to certain areas of cities as they are very dangerous for outsiders and particularly foreigners, these tend to be those poorer black areas. I was told a story by a family member, they were in LA (most people that go to LA don't actually visit LA, the tourist areas are part of the greater LA area, but LA itself is very dangerous) and were heading to the airport. They missed their stop and all of a sudden they could see that almost everyone on the train was black and they were eyeballing them. They decided to get off at the next stop and get the train back the other way and were followed by a man. He stopped them and they were told they shouldn't be there (at this point worrying a lot about their safety) but the man waited with them to protect them until the next train came. A great story of compassion from that man, but also highlighting the danger they were in purely because they missed their stop and went to an area that they shouldn't be in.
www.kff.org