This is an audio recording my dad made on July 17, 1976 of the Southern Railway Liberty Limited ’76 on the B-Line crossing a road to the then-IBM campus off of Wellington Road in Manassas, Virginia. Power for the excursion was Southern 2-8-0 630 and Southern 2-8-2 4501. In the second half of the recording, you can hear engineers on both locomotives playing their whistles.