The major overhaul and construction efforts of the US Navy from the 1890s into the 20th century were dwarfed by those of Germany and England. A massive naval arms race was underway, catapulting the world towards its first world war. When the United States finally was pulled into the conflict in 1917 with the commencement by the Germans of unrestricted submarine warfare, one of the first naval undertakings was the laying of massive mine fields to combat the German submarine force. However, mine warfare was nothing new to the US, because we had been developing and using mines since the Revolutionary War.