...in the 17th and 18th centuries, which you can see if you read contemporary writings. I don't know how the practice started, or why it gradually died out - maybe someone else can explain. I find, though, that unlike German where every noun is automatically capitalized, English writers were not consistent in their capitalization - they'd capitalize some nouns but not others, and sometimes they'd capitalize adjectives, too, but not necessarily the ones you'd expect!