Complex sentence: The Malleco Viaduct, today a National Monument, was officially opened on 26 October 1890 by the then President of the Republic, Manuel Balmaceda, and provided the means for rapid and effective transportation system for trade and commerce.
Split into simpler sentences: The Malleco Viaduct, today a National Monument, was officially opened on 26 October 1890, by President Manuel Balmaceda. The viaduct served as a rapid and effective transportation system for trade and commerce.