Complex sentence: The Sherman Silver Purchase Act did not authorize the free and unlimited coinage of silver that the Free Silver supporters wanted; however, it increased the amount of silver the government was required to purchase on a recurrent monthly basis to 4.5 million ounces.
Split into simpler sentences: The Sherman Silver Purchase Act did not authorize the free and unlimited coinage of silver that the Free Silver supporters wanted. However, it increased the amount of silver the government was required to purchase on a recurrent monthly basis to 4.5 million ounces.