Sandia National Laboratories began as Z Division of Los Alamos in July of 1945. It rapidly grew, becoming Sandia Laboratory, a branch of Los Alamos in 1948 and, a year later, was completely separated from Los Alamos and placed under management of Sandia Corporation, a Western Electric subsidiary.

Sandia's original mission was to design, test, and assemble the non-nuclear components of nuclear weapons. It retains that core mission, although assembly is now done at the Pantex Plant near Amarillo, Texas. It has also built on that core mission and the capabilities that support it, to expand into additional areas of national security like energy research and climate studies. It also plays a significant role in global security, with programs in nonproliferation, monitoring, chem/bio security, cybersecurity, and security surrounding weapons of mass destruction.

Sandia has also expanded in size, maintaining lab sites in both New Mexico and California, as well as test sites in Nevada and Hawaii. It is currently the largest of the U.S. Department of Energy’s national laboratories and of the National Nuclear Security Administration’s nuclear security laboratories.