Cargo pants are identified by several large pockets, most often with button, snap or hook and loop closeable flaps. In addition to multiple front and back pockets, these pants will often have side pockets. They are most often khaki or beige colored and cotton, but can come in other colors and fabrics as well.
Military pants, like those worn by 1940s paratroopers, inspired cargo pants, but only after the style was popularized by a grass roots movement that included an even less-likely candidate for fashion — worker's pants.
In the 1970s, standard issue army pants, which are a form of cargo pants, were very popular with young adults who began purchasing them from Army surplus stores. A similar style also purchased from surplus stores at the time was carpenter's pants or painter's pants, commonly called worker's pants. These utility pants have many pockets like the modern, fashionable pants, but they are less tailored in the leg and lack flaps on the rear pockets. Utility pants also have a trademark twisted loop at the side, which is used by painters to slip in a paintbrush handle, or a hammer for construction workers.
Inspired by the grass-roots popularity of these pants, Levis & Strauss created "bush jeans" in the 1970s — a precursor to today's cargo pants. These were denim straight-legged jeans with large thigh-length side-entry pockets that had smaller square front-facing pockets with snap-down flaps. The back pockets were also deep with snap-down flaps. The main difference between these pants and today's versions is that bush jeans were very slimming, while most cargo pants today have a baggy cut.
Cargo pants are so named because of their ability to carry so much "cargo" in the pockets. The style became so popular that cargo shorts soon followed. The popularity of the style has endured in one form or another since the 1970s. Both comfortable and practical, they have become as much a staple of casual dress as traditional jeans, and are likely to be around for many years to come.