The Amphitrite class monitors were a class of four U.S. Navy monitors ordered as tensions with Spain were rising. A fifth ship originally of the same design, USS Puritan (BM-1), was later fitted with extra armor and designated as a unique class. Though ordered in the mid 1870s, they did not enter commission until the early 1890s. Several variants of the class were created due to modifications in their long service life. These packs contain two variants.