The history of country dance doesn't actually begin in the United States. This quintessentially American dance is, like everything else in the fifty states, a melting pot of other cultures coming together and bringing their disparate influences to form something new.
From the Mother Countries
The primary influence of what we now call country (or "country/western") dance comes from Europe. Settlers from England, Scotland, and Ireland brought forms of dance from the countryside festivals (still performed as "contradance") as well as more courtly dances such as the pavane.
At the same time, African influences were being carried over, especially after the Civil War when many African-Americans traveled west to try and make a new life far from the taint of slavery. This added a syncopation to the rhythms of the music, as well as steps that were more close to the ground and rooted in the earth. It was a vast difference from the elevated floating of the European waltz (or, for that matter, the ballet.
While they weren't as directly an influence, other parts of the world such as Russia and Spain also shared influences on the forms of dance, and even traces of Moorish culture crept into the music and forms of the time. At the height of the cowboy era in the West, music was changing as fast as new settlers arrived, resulting in a truly amazing mishmash of instrumentation and rhythms.
History of Country Dance in America
It shouldn't be thought that only foreign influences caused the look of country dance as it is performed in bars and dance halls today. The way that the dancers move is as much a product of the habits and dress of the cowboys as the signature hat and boots are.
While no one can say for sure, apparently the cowboys loved to dance, so much that when they got to a town after a long time on the trail, they would skip any niceties like bathing or even taking off their spurs before rushing to the dance hall. Many of the open-legged and wide-stanced steps in country dancing, as well as the heel-toe turns, were created in response to the simple needs of dancing in spurs. Likewise, many of the holds in the dance tend to be more hand-to-hand rather than the full-body contact of the waltz, which may have been a result of the ladies trying to protect their clothing from being sullied or even torn by the eager and enthusiastic cowboys.
Another uniquely American addition to the history of country dance is the Caller. With all the new steps being brought in from other cultures, having a man (or, in modern times, a woman) calling out the dance steps as the music changed lent order to the chaos on the dance floor. Often the callers would travel from town to town, becoming celebrities in their own right as they developed the art. Eventually, though, the role of the caller and the steps solidified into what is now traditional square dancing.
Country Western dancing developed into a series of steps performed often with no partners at all, dancers performing in rows and columns. This form of dance became known as "line dancing" and was a direct offshoot of the disco era with its "electric slide." With the release of the hit song "Achy Breaky Heart," line dancing became a flash craze sweeping not just America but traveling to other countries.
Becoming Part of the History
Now country dancing has become a fixed part of the popular dance culture, with lessons offered at many studios and bars. Often dance halls will offer lessons in the early evening for newcomers, teaching the dance principles, then the order of steps and the variations. Since line dancing doesn't require partners or a great deal of athleticism, it's a very welcoming way for people to get involved. Starting with the "Boot-Scootin' Boogie," country western artists have created songs specifically to go along with dance steps. The result has been a rich and vibrant history growing right up into the present day.