Two studies examined how U. S. presidents are forgotten. A total of 415 undergraduates in 1974, 1991, and 2009 recalled as many presidents as possible and attempted to place them in their correct ordinal positions. All showed roughly linear forgetting of the eight or nine presidents prior to the president holding office at the time, and recall of presidents without respect to ordinal position also showed a regular pattern of forgetting. Similar outcomes occurred with 497 adults (ages 18 to 69) tested in 2014. We fit forgetting functions to the data to predict when six relatively recent presidents will recede in memory to the level of most middle presidents (e.g., we predict that Truman will be forgotten to the same extent as McKinley by about 2040). These studies show that forgetting from collective memory can be studied empirically, as with forgetting in other forms of memory.