Tennis sportswear has completely transformed since the sport was introduced to the U.S. in the 1870s. Below is a timeline that is taken from Vogue, looking at fashion over the decades.
The outfit trends started to first be established at the beginning of the 1900s. Here we see a tennis player from that era, the skirts maintained the modesty of a women showing no skin except for a little bit of the arms and neck. Everything from the ankle up was completely covered. In addition, these tennis dresses had corsets built in, which in my opinion must have been extremely uncomfortable to play sport in. The outfits almost resembled something you would be seen wearing in that time off the court as well. The idea of sportswear for females hadn't really been established by this time.
In the 1920s-1930s, the roaring twenties developed a new fashion that included loose fitting and shorter clothing. Here in this picture, tennis players Helen Willis-Moody and Helen Jacobs were seen taking the court in 1929. The tennis outfits start to resemble more of sportswear, giving women more breathing room and allowing them to show more skin. In the 1930s we also saw the introduction of pleated skirts, which was a huge tennis fashion trend.
This picture is from the 1960s. This is when the idea of a tennis dress was introduced. Here we see the hemline getting shorter, arm exposure, and no tights. This is when tennis dress started to shape sportswear into what we see it as today.
Leaping forward to the 1980s, was the introduction of the yellow tennis ball that was introduced so the television viewers could see the ball. This is when tennis players stepped out of tradition white tennis wear, and ventured in to shorter and brighter clothing. The tennis skirt shown in this picture, as well as, collared shirts were trends that we saw up until the 2000s.
This picture shows Anna Kournikova (above) and Maria Sharapova are two tennis players who came famous for their court style in the 2000s. Here we see short skirts, midriff exposure, and tank tops. We also see the introduction of a visor which has stayed a staple in tennis wear up until today. Tennis sneakers also transformed and they style of the tennis sneaker is more developed by this time.
All images and information adapted from Vogue.
http://www.vogue.com/869873/tennis-style-throughout-the-years/
http://www.vogue.com/869873/tennis-style-throughout-the-years/