Is it true that about 100 million Americans received polio vaccines in the late 1950s and early 1960s that were contaminated with monkey SV40 virus?

This is quite true. It has been documented and studied quite closely and reported in the scientific publications. The controversy is only remaining about the consequences for human health and well-being. This was an unfortunate occurrence because monkey kidney cultures were used to propagate the polio virus that was then attenuated and used as an antigen to confer immunity in those receiving the vaccine. Unbeknownst to those researchers, the monkey kidney tissue was infected with the simian virus 40 and that survived the manufacturing process to remain viable. And so all of those early years of vaccination were transferring a foreign virus into people.