Modern day t-shirts evolved out of undergarments worn during the 19th century by cutting the one-piece pajamas of the day into two separate top and bottom garments. The original versions came with or without buttons and were quickly made popular by laborers as they were a great way to cover up, but still stay cool in hot environments. The earliest equivalent of the modern t-shirt came about during the Spanish-American War when white t-shirts were issued to U.S. Navy sailors as an undershirt. The garment quickly gained popularity and its inexpensiveness, in particular, made it a wardrobe staple.
By the 1960s, people began printing their own messages and slogans on t-shirts and they became a popular means of self-expression and/or political protest. As society shifted towards less formality, they became increasingly popular for casual wear. These days, t-shirts are a part of everyone's wardrobe from New York to New Zealand.
This love for t-shirts does, of course, mean that we all have a bunch of old t-shirts that we don't wear anymore but haven't gotten around to throwing away yet. Maybe it has a certain sentimental value (I definitely have some shirts like that!), but those shirts are taking up space in your closet. If you're feeling a little thrifty, however, you could take those old shirts and turn them into a fun bag/purse. Not only is it easy to do, but you could probably even make several and potentially sell a few. Double win!