/r/100yearsago
This subreddit was formed in late 2013 to document World War I, day by day as it developed. It covers social, political, military and cultural developments in combatant countries and noncombatants alike. Its particular emphasis is on pointing out the most striking similarities and differences from the problems humanity faces today.
All submissions must deal with things that happened exactly 100 years ago, using the Gregorian calendar. August 5, 2014 is all about August 5, 1914.
Start the title of your submission with the relevant date in brackets: [August 5, 1915], for example. If you want to discuss the subreddit itself use [Meta].
Follow reddiquette. Be nice to each other.
How can you participate? Search for and post interesting articles from 100 years ago today. You don't have to do it everyday, but each submission helps us learn what was happening a century ago.
Chronicling America: U.S. National Archives newspaper archive
Hathi Trust: Enormous collection of scanned newspapers, magazines and other periodicals
The Gazette: Official public record of the United Kingdom
How to research: The U.K. National Archives' guide to searching newspaper archives
BBC Radio: 1914: Day by Day
/r/100yearsago