J. David Ingles of TRAINS Magazine leads the search for early diesels from five builders. Along the way we'll pause for some rare film of these diesels in their prime. The major diesel builder was and is EMD. You'll see E units, F units, the BL2, and Geeps. Alco is defunct, but you'll find some of the locomotives they built still operating: RS-1s, RS-3s, RSD-15s, and FA power cars. Dave shows you early Center-cabs, rare film of Baldwin's first road switcher, operating RS-12s, and the last of the Sharknoses. Considering the small number of Limas that were built, it's amazing that any still operate. You'll see two Lima switchers that do. An FM H-10-44 diesel that could have been the last in regular service in the U.S. cleans out the remaining cars from a bankrupt railroad. First-generation diesels are around if you can stay ahead of the "ivory hunters.".