From 1973 to 2020, there were over 42,500,000 legal abortions in the US. Using this data to make an average of safe abortions per year to over 900,000 abortions. Meaning that from 1970, it would be over 47,000,000 legal abortions. But the amount of illegal abortions that have happened in the US, we don't know.
https://www.statista.com/statistics/185274/number-of-legal-abortions-in-the-us-since-2000/