Merge sort is an efficient, general-purpose, comparison-based sorting algorithm. Most implementations of merge sort are stable, which means that the relative order of equal elements is the same betwee
Merge sort type algorithms allowed large data sets to be sorted on early computers that had small random access memories by modern standards. Records were stored on magnetic tape and processed on banks of magnetic tape drives, such as these IBM 729s.
Herman Goldstine at The Princeton Institute for Advanced Study (left to right: Julian Bigelow, Herman Goldstine, J. Robert Oppenheimer, and John von Neumann)