A t-shirt has a straight body with sleeves at the top that make the form of the letter "t," hence the name "t-shirt." While similar types of cotton undershirts were worn prior to the t-shirt, they were all sleeveless varieties so were not really "t" shaped shirts, or t-shirts, at all. The United States Navy began having t-shirts made for sailors in 1913 because they wanted something underneath the sailors' jumpers that would cover chest hair.
Civilian men wore a sleeveless undergarment called a singlet. It wasn't until the late 30s that Hanes and Sears Roebuck produced the t-shirt for sale to civilians. Fruit of the Loom started to manufacture the t-shirt in 1938.
Sears offered a 24 cent t-shirt in 1938 designed like a sailor's undergarment. The shirt was called the "gob" shirt; gob was the popular slang term for a sailor in the United States Navy. The gob shirt was advertised by Sears as being suitable to wear as an outer garment rather than only as an undergarment.
When the Marines began to wear the white t-shirt as an outer garment, they soon realized they were too easy for the enemy to spot. Military men used to dye the t shirts with coffee grounds to make themselves better camouflaged. Soon after, standard green military t-shirts were developed and given to the Marines and then the Army.
Military testing was actually done with t-shirts to determine their appropriateness for military service. For example, some members of the military were issued t-shirts and asked for their comments when comparing them with the traditional sleeveless singlet. Most military members preferred the t-shirt shape for many reasons, for example, backpacks were more comfortable at the backs of the shoulders with the t-shirts on and the sleeves allowed for better sweat absorption. Also, the added sleeves protected shoulders from sunburn.
When Marlon Brando wore a form fitting t-shirt as an outer garment in "A Streetcar Named Desire," it caused quite a sensation. James Dean and Elvis also gave the t-shirt a sexy new look and the tighter style that showed the male body became very popular. The t-shirt was definitely a masculine piece of clothing until the 1950s when sporty t-shirts began to be worn by both sexes and were decorated with felt letters for school teams and clubs.
Tie-dyed t-shirts were popular in the 1960s and t-shirts printed with music and television stars were a hit in the 1970s. The basic "t" shape of the shirts stayed the same while necklines changed to scoop, vees, and the sleeves became long or mid-length. Soon the t shirt was available in variations such as designer-decorated with semi-precious stones. Inexpensive and comfortable, the t-shirt, sometimes also spelled tee shirt, remains a part of American culture today.