A good interactive map with models for each state in the US, showing the cases over time and expected number of deaths based on current trajectory and under adapting different levels of social distancing or lockdowns.https://covidactnow.org/
We're already seeing in the data that the social distancing and shutdowns enacted early in Washington and California have had a measurable effect in slowing the spread of the virus. These two states currently double their number of cases every 3.5-4.5 days, versus doubling every 1.5 to 2.5 days elsewhere (New York, New Jersey, Florida):
To put those doubling times into perspective, it means for example that if two states now have 1,000 cases, but one doubles every 4.4 days while the other doubles every 1.4 days, then after 10 days, the former would have 4,800 cases, while the latter would have 141,000.
But as the above site demonstrates, the social distancing is still not enough. It lowers and delays the peak of infections, but still leads to a tremendous overwhelming of ICU capacity and a tremendous number of deaths. More and more states are therefore beginning to apply more extreme levels of lockdown.