Perhaps it is because that is when a train actually began stopping there Mona, so life as such could really begin.
Up until then it had been mainly a mining town which had gone bust I think. The first train stopped in 1870 and by the mid 70's it had become a really active and exciting place to be.
Ages ago German TV repeated an old TV mini-series called "Centennial" with David Janssen, and that at least is how the Colorado from the time was portrayed..............but there is no doubt that Beetle will know the actual reason.
Avatar: HOHENZOLLERNBRÃœCKE Cologne with CATHEDRAL and LUDWIG MUSEUM. The Bridge a symbol of how Germany was rebuilt after WWII, it was left in ruins, the Cathedral with roots in the 13th century represents the country's history, Museum of Modern Art the present day.