With all due respect, ladies, you're talking with someone who was born and raised in New York City and never once entertained the notion of purchasing the Brooklyn Bridge. In other words, save the Sermon on the Count for the congregation. The creative accounting you cite (and no doubt sincerely believe -- I don't doubt your sincerity for a moment, mind you) is just too counter-intuitive for my intellectual taste. That an act both illegal and morally suspect in one cultural context was performed with the same frequency as an act both legal and socially approved in another cultural context -- this is stuff only your fellow travelers will buy into, I'm afraid. No doubt the same sort of creative statistics could support an anti-temperance talking point that as much alcoholic consumption took place during National Prohibition as rakes place today. But it wouldn't be true.
At any rate, your argument is supererogatory, addressed as it is to someone who believes abortion should never have been declared illegal, and who believes that it must remain legal.
My quarrel is with Abortion Culture. With the moral dereliction of American culture. Even granting your creative statistics concerning pre-legalization, the best your argument can do is show that America was morally derelict throughout. Which does not refute my contention that America is morally derelict today, you see.
In 1970 abortion was illegal in 30 states. Twenty states had varying degrees of legality: 1 state for rape only, 2 states for health risk of mother only, 13 states for rape, incest, health risk for mother and/or fetus, 4 states on request. The CDC weekly bulletin reported quarterly statistics for legal abortions only. Illegal ones were not reported.
“A total of 99,721 legal abortions were reported for the entire United States between Jan,1 and March 31, 1971 .”
Center for Disease Control vol 21 number 4; week ending April 8, 1972: “Morbidity and Mortality: page 118
Google Books
The above number of abortions is for 3 months only. Assuming that monthly abortion numbers are fairly similar the rest of the year multiplying by 4 gives an estimate of the year’s total number of abortions of about 400,000 legal abortions. Making a rough guesstimate that there were half again as many illegal abortions in the 30 states that banned abortion the total probable number of abortions was 600,000
In 2016, 623,471 legal induced abortions were reported to CDC from 48 reporting areas.
CDCs Abortion Surveillance System FAQs | CDC
Abort73, an anti-abortion site, says there were 890,000 abortions in the US in 2016. This may be true. For some unclear reason not all abortions are reported to the CDC.
Facts About Abortion: U.S. Abortion Statistics
So, in 2016 with a total population of 328M and 890,000 abortions .27% of the population gets abortions.
Fifty+ years ago with a total population of 205M and 600,000 combined legal and illegal abortions .29% of the population got abortions.
So, no making abortion legal hasn't created an abortion culture. It didn't increase the number of abortions it didn't increase the rate of abortion.