The awards take their name from the 1934 short story "Sidewise in Time" by Murray Leinster, in which a strange storm causes portions of Earth to swap places with their analogs from other timelines.
The awards were created by Steven H Silver, Evelyn C. Leeper, and Robert B. Schmunk. Over the years, the number of judges has fluctuated between three and eight, including judges in the UK and South Africa.
Each year, two awards are presented, usually at the World Science Fiction Convention. The Short-Form award is presented to a work under 60,000 words in length. The Long-Form award may be presented to a work longer than 60,000 words, including both novels and complete series. At their discretion, the judges may also elect to recognize an individual or work with a Special Achievement Award in recognition of works that were published prior to the award's inception.