Sentence:  But it had , as was usual in southern cities of this <WSD>sort</WSD> , a Black Bottom , a low region near the river where the Negroes lived - servants and laborers huddled together in a region with no sewage save the river , where streets and sidewalks were neglected and where there was much poverty and crime . 
Meaning of the word marked with <WSD> tags:  a category of things distinguished by some common characteristic or quality