Complex sentence: He attended Bryant & Stratton Business College in St. Louis for one year, taking a commercial course, and subsequently clerked in a hardware store in St. Charles and was connected as a part of the St. Charles Mercantile Company for one year.
Split into simpler sentences: He attended Bryant & Stratton Business College in St. Louis for one year, taking a commercial course. And subsequently clerked in a hardware store in St. Charles and was connected as a part of the St. Charles Mercantile Company for one year.