In this report we present corrected acceleration, velocity and displacement curves for recordings in the free-field or in basements of buildings. This data was recorded in the Western United States between 1933 and 1971.; Acceleration, velocity and displacement curves presented here differ from those presented in Volume II, Parts A through Y (Hudson, 1976). In those reports, a uniform frequency band between 0.07 Hz (or 0.125 Hz) and 25 Hz has been chosen for all records. In this report, each record is analyzed separately. Whenever the signal becomes smaller than the amplitude of average plus one standard deviation of digitization noise, the original low-frequency limit (0.07 Hz or 0.125 Hz) is replaced by a higher cut-off frequency to eliminate digitization and processing noise. For many records, this improves the accuracy with which computed velocity and displacement curves approximate actual ground motions.