  The intent of this paper is to discuss the history and origins of Lagrangian
hydrodynamic methods for simulating shock driven flows. The majority of the
pioneering research occurred within the Manhattan Project. A range of
Lagrangian hydrodynamic schemes were created between 1943 and 1948 by John von
Neumann, Rudolf Peierls, Tony Skyrme, and Robert Richtmyer. These schemes
varied significantly from each other; however, they all used a staggered-grid
and finite difference approximations of the derivatives in the governing
equations, where the first scheme was by von Neumann. These ground-breaking
schemes were principally published in Los Alamos laboratory reports that were
eventually declassified many decades after authorship, which motivates us to
document the work and describe the accompanying history in a paper that is
accessible to the broader scientific community. Furthermore, we seek to correct
historical omissions on the pivotal contributions made by Peierls and Skyrme to
creating robust Lagrangian hydrodynamic methods for simulating shock driven
flows. Understanding the history of Lagrangian hydrodynamic methods can help
explain the origins of many modern schemes and may inspire the pursuit of new
schemes.
