Historically, was there ever a time when Korean didn't use spaces between words? If so, what time period? When were spaces first introduced? Because spaces didn't exist until the 9th+ century in the West.
According to the National Institute of the Korean Language, spacing was used at first in Korean by the English pastor John Ross in the book 'Corean Primer' in 1877.
The first spacing is almost the same as today's spacing. It's been said that the newspaper “The Independent” written by Seo Jae-pil, Joo-kyung Joo, and American missionary Herbert in 1896 was the first publication to spread spacing in Korean.
The spacing of Hangeul became universalized with the 'Korean Spelling Unification Plan(한글 맞춤법 통일안)' by the Korean Language Society (조선어학회) in 1933. https://blog.naver.com/dsticorp/221438395490