If you go back and look at some newspaper headlines from when the 1918 flu was ramping up, it looks strikingly similar to the news headlines now.
The lesson from back then is that distancing/quarantines do help to "flatten the curve", but it has to be done early and aggressively. Philadelphia was very slow to act back then and they had a much higher illness/death rate than other places in the US that acted more quickly. St. Louis acted quickly and they were able to keep their rate on the lower side. But one thing to learn from St. Louis is that they started to loosen their restrictions after about 6 weeks, and then there was an immediate spike in cases there. So the 8 week guidance that has come out from the CDC seems long, but past experience suggests it may even need to go on longer.