The Railway Express Agency (REA) was a the national monopoly set up by the Untied States federal government in 1917. Rail express services provided small package and parcel transportation using the extant railroad infrastructure much as UPS

UPS

- Science, technology and medicine :* Uninterruptible power supply* Ubiquitin proteasome system* Ultraviolet photoelectron spectroscopy* Universal Polar Stereographic coordinate system* Ups * Medically "unexplained physical symptoms"...

 functions today using the road system. The United States government was concerned about the rapid, safe movement of parcels, money, and goods during World War I

World War I

World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...

 and REA was its solution to this problem.