Although the use of footlights in the theatre can be traced back to the 17th century, it was during the years just prior to the modernist era that they became synonymous with the stage itself. For example, Olive Logan's 1870 memoir was titled Before the Footlights and Behind the Scenes, and Otis Skinner's in 1923 was Footlights and Spotlights. The row of lights set into a trough across the front of the stage complemented lighting from above the stage so that actors would not have harsh shadows beneath the brow and chin. Many actors believed that footlights erased wrinkles and brightened the eyes. The type of footlights described in The Autobiography of Joseph Jefferson could still be found in rural areas during the early modernist period: "The footlights of the best theaters in the Western country were composed of lamps set in a 'float' with the counter-weights. When a dark stage was required, or the lamps needed trimming or refilling, this mechanical contrivance was made to sink under the stage" (Jefferson 1964, 27). Like other lighting components, footlights progressed from candles to oil lamps to gas to electricity.
The Historical Dictionary of the American Theater. James Fisher.