The 1880 US census data is now online and available for free searching. I spotted this the other day via Metafilter and did some quick poking around to see if I could find any ancestors. Lo and behold, I turned up Charlie Curtiss (living at the time with Henry Coolidge and family). Charlie would go on to marry Henry's daughter Lizzie in 1886. My great-grandmother Lottie Curtis would be born six years later. I also turned up Charlie's father (my great-great-great grandfather) Sumner Curtis living with his wife Angeline (Rice) Curtis in Vermont but the site is so overwhelmed I can't get that data to load now.
It's pretty cool to be able to find this stuff online, and also interesting to see the discrepencies in the data. Our family bibles (from which I built branches of my family tree several years back) lists "Charlie Curtiss" as "Charles Sumner Curtis" (one S). And "Lizzie D. Coolidge" is recorded as "Lizzie Gray Coolidge." I can almost picture my great-great-grandmother say "G" with a strong accent that caused the census taker to write down "D" instead. It's amazing what stories I can concoct for these ancestors just by seeing their census data online.