https://history.state.gov/milestones/1866-1898/spanish-american-war
https://nationalmap.gov/small_scale/mld/usacqup.html
http://www.history.com/this-day-in-history/puerto-ricans-become-u-s-citizens-are-recruited-for-war-effort
https://www.loc.gov/rr/news/topics/spanishAmWar.html
http://www.history.com/topics/spanish-american-war