Where can I watch Late Night with David Letterman in United States?

Late Night with David Letterman is a nightly hour-long comedy talk show on NBC that was created and hosted by David Letterman. It premiered in 1982 as the first incarnation of the Late Night franchise and went off the air in 1993, after Letterman left NBC and moved to Late Show on CBS. Late Night with Conan O'Brien then filled the time slot. As of March 2, 2009, the slot has been filled by Late Night with Jimmy Fallon. It will be filled by Seth Meyers in the spring of 2014, after Fallon becomes host of The Tonight Show.