Note: Multi-Category Award. Given annually for the best science fiction or fantasy works and achievements of the previous year. The award is named after Hugo Gernsback, the founder of the pioneering science fiction magazine Amazing Stories, and is (with the Nebulas) one of the premier awards in speculative fiction. Hugo Award nominees and winners are chosen by members (supporting or attending) of the annual Worldcon.
Originally titled the "Science Fiction Achievement Awards", they were first presented at the 1953 Worldcon. While it was hoped that the awards would become an annual event, no awards were given in 1954, but were resumed the following year at the 1955 Worldcon.
Rules for this award, including the category names were specified in the World Science Fiction Society (WSFS) Constitution beginning in 1961. The earliest version of the WSFS Constitution found online is from 1963. Category names for awards prior to that are taken from the Worldcon program book for that year, or the official Hugo Awards site.
The 1990 award for Best Original Artwork was described as "not a Hugo" in the 1990 Worldcon program book. However, both the official website and subsequent Worldcon documents refer to it as an official award. It was presumably a special award that year as it did not become an official category until 1992.
