More blacks in northern New England

This post is somewhat a continuation of my thread on more blacks in lily white states or areas on the previous board. How could northern New England- Maine, New Hampshire and Vermont- have attracted larger nos. of blacks at any point from the Revolutionary War, such that there'd be a northern NE major city boasting a significant black pop the equivalent of say Boston or Hartford ? I came across a website the other week on African-Americans in Maine, who apparently although small numerically did play a tangible role in the whaling industry, and apparently most settlements in Maine had black ppl living in them, if only with 1 individual person or a family. Could the northern NE states have developed any manufacturing industries, albeit on a smaller scale, as was found further west in big Midwestern cities like Chicago, Detroit, and Cleveland, which'd attract an outflux of black Southern migrants during the 2 WWs ?

I also recall reading an article on the BHD website I used to be part of, which claimed that in 2002 a fair few Somali refugees were wanting to settle in Maine.

Economic opportunities

You might have got a lot of black people into Pennsylvania if the industrial revolution took off very quickly. Say the Revolutionary war lasts till 1781 and there are so many British army freed blacks that the idea of reinslaving them is impossible. We also get a centralist federal government. The Capitol is at Great Falls on the Potomac and we build a wide guage railway around the falls too move boats past the rapids. The federal government encourages industrialization deliberatly to build up the country's industrial and military capabilities.
So we get railroads right downstream from massive coal deposits and through the capitol city.

2 changes I could see potentially-The New Hampshire primary would have much more demographic relevance and perhaps there would be more African-American hockey players

I remember Al Sharpton attacked Dean for not having any blacks in his Cabinet while governor and Jesse Jackson pointed out that there aren't many blacks in NH, period.

This ATL should change that.