The late fees are probably over a million dollars.
In the 1960s, when I first started having to deal with library overdue fines, I remember two cents a day as being a typical amount. If that had been the fine in 1903, the total would only be about $877 for 120 years. I never heard of a library charging compound interest on fines.
It was 1903. They may not have charged late fees then. And if they did, one could argue that it's the 1903 rate at the time of checkout that should be used without subsequent increases. Especially if there was no notice of increase given to the borrower.