A methodology has been developed at the U.S. Geological Survey (USGS) for making earthquake catalogs for seismic hazard analysis. A new catalog is assembled from several preexisting catalogs. Uniform moment magnitudes and related parameters for estimating unbiased seismicity rates are calculated. Duplicates, explosions, mining-related earthquakes, and induced earthquakes are flagged, and the catalog is declustered. Distinct catalogs are made for the central and eastern U.S. and the western U.S. This data set is the master earthquake catalog composed of several pre-existing source catalogs for the central and eastern U.S.