Earthquakes of M ≥ 2.7 (1975-2000) in the accreted-terranes region of the northeastern United States are more temporally clustered than expected from a random process. This clustering is evident even when aftershocks have been removed from the earthquake catalog. The distances between clustered event pairs are uniformly distributed between 20 km and over 400 km. It is not clear why this clustering is occurring. Curiously, statistically significant temporal clustering was not found for earthquakes from nearby Quebec on the North American craton.