dell-research-harvard/AmericanStories · LCCN Data for Later Years?

Hi folks! This is a really exciting dataset—I'm a computational historian of the 19th/20th Century US, so the problem with non-split articles in Chronicling America has been on my mind for years. I'm delighted that you've seemed to have solved it! A quick question-- is there a way to access the LCCN data for articles in the later years? I want to iterate through the JSON and use regular expressions to pull out mentions of various things, but right now, there seems to be no way within the data to link that back to the broader newspaper meta-data. The readme suggests that you have that data for years like 1870, but when I grab the files, it doesn't seem to be there in the JSON. Any help you can give will be greatly appreciated!