A small park overlooks what used to be the crossroads of the world. Gently singing birds and tourists, both en route to somewhere else, pass by what once were the stinking, crowded roads of America’s fourth largest shipping port. Visitors to this corner of New Bedford might see the sign, “CAPTAIN PAUL CUFFE PARK,” on the small terrace that now presides at the intersection of a brewpub and a YMCA parking lot.