The US Geological Survey has a great site with all kinds of historical data and information about past earthquakes. For example, here’s a list of all US quakes ranked by magnitude: click.
In terms of a US example that comes anywhere close to an 8.8 in a populated area, one would have to go to the 1906 San Francisco earthquake, which was a 7.8.
In terms of more recent comparisons, and to demonstrate how much larger the Chile quake is, I am taken back to the 1994 Northridge earthquake, which did extensive damage in Southern California, and it was only a 6.7. That was the last time that I recall a California quake causing sufficient damage to make significant national news. I had already moved out of SoCal by the time that one hit, but recall that it was bad enough to warrant massive national news coverage.
Some may recall the Santa Cruz Mountains/Loma Prieta earthquake, which occurred right before a World Series game in 1989 (see more here). It was a 6.9 and famously caused portions of the double-decker San Francisco – Oakland Bay Bridge to collapse.
The largest earthquake that I personally experienced in California was the 5.9 magnitude Whitter Narrows Earthquake.
The quake that most got my attention, was a 6.5 near Bogota. My wife and I were in our apartment, which was on the 6th floor (IIRC) and the building was swaying rather dramatically. It caused quite a stir, as bogotanos aren’t used to feeling earthquakes and it caught the city’s attention, to be sure.
