On March 8, 1971, The Florence Times—Tri-Cities Daily reported that left-handed people “are becoming increasingly accepted and enabled to find their right (or left) place in the world.” The Florence Times—Tri-Cities Daily also wrote “we still have a long way to go before the last vestiges of discrimination against left-handedness are uprooted, however.” The frequency of left-handed writing in the United States, which was only 2.1 percent in 1932, had risen to over 11 percent by 1972. According to an article by The Washington Post from August 13, 1979, a University of Chicago psychologist, Jerre Levy, said: “In 1939, 2 percent of the population wrote with the left hand. By 1946, it was up to 7 1/2 percent. In 1968, 9 percent. By 1972, 12 percent. It’s leveling off, and I expect the real number of left-handers will turn out to be about 14 percent.” According to the article by The Washington Post from August 13, 1979, “a University of Michigan study points out that left-handers may not be taking over the world but…7 percent of the men and 6 percent of the women over 40 who were interviewed were lefties, but the percentages jumped to well above 10 percent in the 18-to-39 age group.” According to the article by The Washington Post of August 13, 1979, Dr. Bernard McKenna of the National Education Association said: “There was recognition by medical authorities that left-handedness was normal and that tying the hand up in a child often caused stuttering.” In Japan, Tokyo psychiatrist Soichi Hakozaki coped with such deep-seated discrimination against left-handed people that he wrote The World of Left-Handers. Hakozaki reported finding situations in which women were afraid their husbands would divorce them for being left-handed. According to the aforementioned article, an official at the Japanese Embassy said that, before the war, there was discrimination against left-handers. “Children were not trained to use their left hand while eating or writing. I used to throw a baseball left-handed, but my grandparents wanted me to throw right-handed. I can throw either way. Today, in some local areas, discrimination may still remain, but on the whole, it seems to be over. There are many left-handers in Japan.” In a further article in The Washington Post of December 11, 1988, Richard M. Restak wrote that left-handedness has become more accepted and people have decided to leave southpaws alone and to stop working against left-handedness. In an article by The Gadsden Times from October 3, 1993, the newspaper mentioned a 5-year-old named Daniel, writing: “the advantage that little Daniel does have of going to school in the '90s is that he will be allowed to be left-hander. That wasn’t always the case in years past.” In a 1998 survey, 24 percent of younger-generation left-handed people reported some attempts to switch their handedness.
If you’d like to know a whole lot more, here’s a Wikipedia page that could probably use some editing and reorganization but has over 80 references showing bias against lefties throughout history
A sample,