Kick your holidays into high gear with these facts about America’s most famous dance troupe: the Rockettes, a part of Christmas for millions.

The Missouri Rockets

The Rockettes’ performance home base has been Radio City Music Hall in New York City since the 1930s, which explains its association with the city that never sleeps. But the troupe’s history goes back to St. Louis. Local promoter Russell Market formed the troupe in the Missouri metropolis back in 1925. He called them the Missouri Rockets.

The Roxyettes

Those early Missouri Rockets embarked on a national tour, which played New York City. Among those dazzled by the group’s precision, uniform dancing was a local impresario named S.L. “Roxy” Rothafel. He bought the rights to the Missouri Rockets from Market, moved the group to New York, and renamed them the “Roxyettes” after himself…before combining the old moniker with the new one to create “Rockettes.”

The kickline

What made the Rockettes unique was its dazzling uniformity — dozens of dancers filling a stage, all doing the same thing, notably a “kickline” in which all of their legs moved at the same time to the exact same height. This was a holdover from a style of dancing that became popular in the staid, conservative Victorian era of England in the late 1800s. As a response to scantily clad showgirls, a troupe called the Tiller Girls found popularity for wearing more clothes and dancing in near-robotic unison. Russell Market explicitly set out to create America’s own version of the Tiller Girls.

Christmas Spectacular

The most famous Rockettes show is its annual “Christmas Spectacular,” which involves not just dancers but elaborate sets, costumes, and even animals. Even so, the Rockettes perform throughout the year. The troupe was once a fixture of movie openings at Radio City, performing at more than 700 premieres from the 1930s on.

Physical Guidelines

To get that uniform look, the Rockettes does have some steadfast physical guidelines for its dancers. Women must have a height between 5’6” and 5’10”. Their placement on the stage is specifically tied to minimizing the optics of those differences, and the kickline is choreographed so all of their legs reach the same height — that might be more or less of a “distance” depending on the dancer’s height.

Skin Color

Until relatively recently, Rockettes were also just one skin color: white. Seeking out a group that looked as much like each other as possible, earlier organizers took only Caucasian performers and went so far as to ban suntans.

The First Non-White Rockette

First non-white Rockette: Japanese dancer Setsuko Maruhashi, who joined up in 1985.

Little turnover

There are spots for 80 Rockettes, but there’s little turnover. So many dancers opt to return that only one or two slots open up to new talent each year.