From 1800 until the mid-1900s, things were going just fine for the comb-over. President William McKinley, who was elected in 1896, had something of a comb-over, as did General Dwight D. Eisenhower during World War II. Actors had them too, including Zero Mostel and Don Rickles, both of whom sported them from the 1950s until the late 1970s (when Mostel died and Rickles opted to just be bald instead).
There was also something of a strange entry in comb-over history in 1977, when Frank J. Smith and his son Donald J. Smith patented the comb-over. Though the hairstyle was nothing new at the time, the duo developed a complex, almost Trumpian version that involved not just combing the hair over from one side, but from both sides and the back. Apparently, they thought it was so innovative that it should be patented and, even more surprisingly, the U.S. Patent Office agreed.
Unfortunately for them, the hairstyle didn’t catch on — by 1977, the comb-over was already in decline. Hair plugs, which came about in the 1950s, played a major role. They were pretty shitty and noticeable at first, but over the next few decades, plugs would gradually become more natural-looking. There was also the invention and popularization of Rogaine, which began to be prescribed for balding in the 1980s and was officially approved for this purpose by the FDA in 1988.
But perhaps the most significant change came about in fashion, as men with entirely bald heads became acceptable in the second half of the 20th century. The man most widely credited as beginning the trend was Russian-born actor Yul Brynner, who shaved his head in 1951 for his role in the Broadway play The King and I. Brynner was already losing his hair when he got the part as the King of Siam at age 30, and the costume designer for the play suggested he shave his head completely, wrongfully assuming that the real King Monkut had been bald. Although the script never called for a bald king, Brynner’s shiny head made him look especially striking, so he kept it for all 4,625 of his performances in the part, as well as for the 1956 film, for which he won an Oscar.