Catalan inventor Narcís Monturiol fought for ideals like equality, freedom, and progress in the midst of a lot of social and political chaos in 19th-century upheavals in Spain and Catalonia. And then, he built submarines.
Research:

Elizabeth Blackwell's Curious Herbal
34:51

The Many Meanings of the Bunker Hill Monument
45:48

SYMHC Classics: Four Paperclippers
36:24