I encountered a sentence:
With the invention of the printing press in 1440 by Johannes Gutenberg the nature of bookbinding changed. More books were produced and the binder had to find new, faster methods to bind and decorate them. In 1861 David Smyth invented a book sewing machine. While the trend of mechanized binding continues today, there are still craftspeople who bind books by hand and much of modern hand book binding owes a great debt to the 19th century Arts and Crafts movement.
My problem is in understanding the last sentence. (emphasis mine). What does "owes a great debt to the 19th century" mean?