Slice of History is a term used to describe a period of time in the past that has been preserved and documented. The crossword solutions for this term are EON (3 letters), AGE (3 letters), ERA (3 letters), and EXTREMEMEASURES (15 letters). EON refers to an indefinitely long period of time, AGE is a period of time marked by a particular characteristic or event, ERA is a period of time marked by a particular set of circumstances, and EXTREMEMEASURES is an expression used to describe drastic measures taken to achieve a desired result.