In this article, I attempt to focus on the chronology of seismic imaging. I start in the mid-1920s, progress through the human "computer"-based methods of the 1940s and 1950s, discuss the emergence of digital wave-equation technology in the 1960s and early 1970s, and finally end with a review of the present. I include a bit of speculation about the future of seismic imaging, but the meat of the article is on seismic-imaging history. Based on the timing of their publications, I claim there are three key contributors to the theoretical developments of modern seismic imaging: F. Rieber, J. G. Hagedoorn, and J. F. Claerbout. None of these men were the first to consider the seismic-imaging problem, but their papers and algorithms have probably been quoted more often than anyone else's. One certainly must give credit as well to C. H. Dix and M. M. Slotnick for similar contributions. Other names that come to mind include Hans Sattlegger in Germany, A. J. Berkhout in the Netherlands, Bill Schneider at GSI in Dallas, and Robert Stolt at CONOCO in Ponca City, Oklahoma. However, without the independent computational progression predicted by Moore's law (computer speed doubles every 18 months), the spectacular subsurface images produced today would not be possible. I hope to convince the reader that in addition to the development of the vast literature on seismic-imaging theory, another, less-publicized, parallel technological progression has focused on the development of efficient machines to produce, with minimal human intervention, an increasingly more accurate image of the strata below the recording instruments. Unfortunately, with a few key exceptions, the names of many of the contributors to this aspect of seismic imaging have been lost. The digital revolution in the 1960s appears to be the culmination of this attempt at mechanization, but not until the development of truly powerful scientific computers did the more accurate and advanced theoretical developments in seismic-imaging theory become practical to apply and use in the search for diminishing supplies of hydrocarbons. In fact, one can argue that we still don't have sufficient computer power to do everything we need and want to do. But that's another story.