If Seaway confined itself only to African-American buyers today, the pool of potential suitors might be even slimmer than when Mr. Dickens tested the waters. There are only two African-American-owned banks larger than Seaway — one in New York and one in Boston. One of those, Carver Federal Savings Bank in New York, survived the recession only after a $55 million bailout in 2011 by Goldman Sachs Group Inc., Morgan Stanley and other big New York financial firms.