I wasn't around yet, but I am told that 50 years ago today a paper by J.C.Kendrew et al. appeared in Nature describing the first ever crystal structure of a protein, which was of course myoglobin.
This was made possible by more than three decades of research by Max Perutz and others at the LMB in Cambridge. Perutz himself had his sights set on haemoglobin, which is larger and more difficult and took a few years longer.
Today, of course, there are tens of thousands of crystal structures of proteins in the protein data bank (which today lists 41,915 Xray structures of proteins and nucleic acids), and some papers contain structures of several proteins or of huge assembly systems, sometimes only attached as one of several ways of characterizing the system in question.
Oh well. What I find most remarkable in this story is that it took 36 years or so from Perutz's start to the first structure. Try explaining to your funding agency today, if you don't have final results after 2 years, that it may take another 34 years to get there.