Sentence:  From its <WSD>inception</WSD> in 1920 with the passage of Public Law 236 , 66 th Congress , the purpose of the vocational rehabilitation program has been to assist the States , by means of grants-in-aid , to return disabled men and women to productive , gainful employment . 
Meaning of the word marked with <WSD> tags:  an event that is a beginning; a first part or stage of subsequent events