It was 2013, and American writer and translator Liz Castro was a link in that chain.
She said it was one of the most remarkable experiences she's had fighting to make her adopted home a new European nation.
"I think we really proved to ourselves that we had this mobilizing ability, this organizational capacity," she said. "And people were happy."
The positive spirit of the Catalan separatist drive is what Castro aimed to capture, through anecdotes and more than 500 photos, in her recently published book, "Many Grains of Sand: A sourcebook of ideas for changing the world, tried and tested in Catalonia." She wrote English and Catalan editions of the book.
Castro, whose great-grandparents immigrated to America from southern Spain in the early 1900s, started learning the Catalan language as a college student. She visited and then moved to Barcelona in 1987, married a local and then moved to western Massachusetts in 1993, raising multilingual children.