The Early Days: 1900s-1940s
3D technology actually dates back to the very beginning of film. The earliest 3D film was produced in France in 1903 and was called "L'arivee du train". It included, as one might expect, the arrival of the train. It took advantage of three-dimensional photography technology from the nineteenth century called "anaglyphic" technology, which uses overlapping blue and cyan colors and glasses to create a three-dimensional illusion.
However, for the first fifty years of film, three-dimensional films were never commercially viable. The process for making them was very expensive and the audience never warmed up to them. Rather, the developments in film technology focused on developing sound and then color, rather than three-dimensionality.