It is the soothing thing about history that it does repeat itself. ~ Gertrude Stein
The web is the place of now. When we open our phones or tablets or laptops, it's usually to find out what's going on at this very moment. That can be a vicious cycle (since now never ends). Imagine the brief respite, then, that a little history would offer.
That's precisely what Collective History does. It's run by an historian who, frankly, knows what she's talking about. The tumblog presents historic images with just a bit of backstory, like this stamp celebrating the origin of Women's Equality Day:
... or a photo of a girl resting during the evacuation of Barcelona in 1939. The Tumblr has infinite scroll, so you can bookmark the site and visit it when you want. I, however, recommend throwing it in your RSS reader. Most of us use our readers to catch up on news, which epitomizes the now, now, now mentality. Collective History can throw a well-placed oasis in the midst of your reader. Every time I scroll through my reader and see an image come up from this site, it slows me down. I pause, take a breath, and remember that my world has a rich and intricate history. It's a little splash of awe in the usually mundane world of online news.