Sorry, but the chart on this site is an overt lie.
There were not over 50,000 cases of polio in the US in the year 1986. There were not even 150 cases that year. What the chart shows is that polio basically disappeared in 1979. From 1980 to 2002 there were approximately 8 cases per year in the US. What he did was to past world wide cases onto the last part of the chart.