Complex sentence: The building was built as a saloon in the 1900s by a Scottish stonesman for Pierre Guillaume, but when a law was passed in 1906 prohibiting sale of alcohol within a mile of a veteran's home Guillaume sold the building.
Split into simpler sentences: The building was built as a saloon in the 1900s by a Scottish stonesman for Pierre Guillaume. When a law was passed in 1906 prohibiting sale of alcohol within a mile of a veteran's home, Guillaume sold the building.