British blogger Chris Wild captures the feminization and eroticization of cheerleading with a telling collection of photographs. He starts with vintage images from the 1920s when men stood on the sidelines leading fans in cheer, and ends with modern-day photos of sweaty N.F.L. cheerleaders showing lots of skin in halter tops and miniskirts. Check out the series that originally ran on Wild’s site Retronaut

Super Bowl XLVI is upon us. Soon football fans across America will tune into NBC and all eyes will be on the New England Patriots and the New York Giants facing it off on the field.

On the sidelines cheerleaders—shaking their pom-poms and their hips—will root for the teams. Actually, the New York Giants don’t have a squad but the Patriots’ cheerleaders, who were named this year’s top squad by CNBC, are sure to offer up an entertaining dose of off-field action on February 5.

Most N.F.L. cheerleaders these days are known for their tight abs, sexy outfits, and highly choreographed dances, and some teams like the Giants don’t have dancing women on the sidelines for this reason.

“Philosophically we have always had issues with sending scantily clad women out on the field to entertain our fans,” John Mara, the Giants co-owner, told the Times in 2010. “It’s just not part of our philosophy.”

Cheerleaders weren’t always known for their provocative outfits and moves. Men initially led fans in cheers. A University of Minnesota student named Johnny Campbell was the first-ever cheerleader. In 1898 he picked up a megaphone and directed a crowd in cheering: “Rah, rah, rah! Ski-U-Mah! Hoo-Rah! Hoo-Rah! Varsity! Varsity! Minn-e-so-tah!” His catchy chant led the football team to victory, and modern-day cheerleading was born.

In the 1920s women picked up pom-poms. Cheerleading eventually became a female-dominated activity. Women wore long pleated skirts, falling well past the knee, and started adding acrobatic stunts to their routines.

The sexy outfits didn’t arrive until the 1970s, according to British author Chris Wild, who captured the evolution of cheerleading in a photo series (above) on his blog Retronaut. “This was a time when feminism was a strong force, and barriers for women in Western society were being dismantled,” Wild says.

Over the years N.F.L. cheerleading outfits have only gotten skimpier. “Cheerleading seems to have acted, either positively or negatively, as a pressure valve, letting women into the stadium and into the game,” Wild says, “But keeping the difference between the men in their helmets and the women in their short skirts very very clear.”

High school and college cheerleaders are quick to point out that they’re unlike the girls on the professional football fields. Competitive cheerleading team members are athletic, filling their routines with flips, pyramids, and impressive acrobatic stunts that require guts. Some national cheer organizations have stepped forwarded demanding that cheerleading be recognized as a sport.