Sentence:  In March , 1961 , representatives of the national laboratories of Australia , Canada , The Netherlands , United Kingdom , U. S. S. R. , <WSD>United</WSD> States , and West Germany , met at the NBS to devise means for reaching international agreement on a temperature scale between 10 and 90 * * f . 
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