Sentence:  It was the low yield of the Selkirk plots and the ravages of grasshoppers in 1818 that led to the dispersal of the <WSD>settlement</WSD> southward . 
Meaning of the word marked with <WSD> tags:  a body of people who settle far from home but maintain ties with their homeland; inhabitants remain nationals of their home state but are not literally under the home state's system of government