Sentence:  Oliver , in his summary of the habits of the snakes of the <WSD>United</WSD> States , could supply data on the maturing period for only three species in addition to the rattlers , which I shall consider separately . 
Meaning of the word marked with <WSD> tags:  North American republic containing 50 states - 48 conterminous states in North America plus Alaska in northwest North America and the Hawaiian Islands in the Pacific Ocean; achieved independence in 1776