Lionel S. Beale of London made some of the earliest contributions to Cytopathology in the 1850–1860s. Cytopathology then experienced a 60+ year hiatus during which few advances were made. In 1927, Londoner Leonard S. Dudgeon published his wet film method for rapid intraoperative diagnosis and in 1928 Greek‐American George Papanicolaou and Romanian Aurel A. Babeş independently discovered that cervical cancer can be diagnosed using vaginal smears; these were huge advancements. Yet, there was another hiatus where little progress was made which lasted until the publications of Papanicolaou and Trout in the early 1940s. After that, the field of exfoliative Cytopathology immediately flourished. None of the standard histories of Cytopathology explain these two gaps. Primary and secondary historical sources were examined to explain this pattern. The author concludes that the first hiatus is explained by the 19th Century pathology establishment's strong opposition to the doctrine of the uniqueness of cancer cells that was being pushed by only a few maverick pathologists; in fact, for many mainstream pathologists, cancer was rigidly defined by cell behavior (metastases and invasion) and not cell morphology well into the 20th Century. Biopsy‐based diagnosis faced similar opposition but advanced more rapidly as it was possible to examine increased numbers of cells in a pattern that partially maintained their normal adjacencies and architecture. The second hiatus is explained by economic pressures supporting intraoperative frozen section diagnoses and, in the instance of vaginal smears, the embryonic state of the public campaign supporting the importance of early cancer diagnosis. Diagn. Cytopathol. 2015;43:257–263. © 2015 Wiley Periodicals, Inc.