WellCookedFetus said:They only said they had plans for a subway "experiment", it does not say they carried it out.
All 5 US military and US government sites that I found agree that they carried it out. One US military site says:
...the United States conducted a sequence of highly classified scientific tests on unknowing populations throughout the country, with agents and materials believed to be nonpathogenic. In fact, not until early 1977 was the extent of the military biological weapons testing program publicly disclosed before Congress.
I shouldn't have to provide a link for something so easy to find on Google; that gets tiring. Still, I will if you can't find it.