We didn't know how much it was spreading in the US because we weren't testing cases that didn't have a nexus to China/SK. So we had no idea what the spread was like and there was no data to go on to inform decisions to lock down. Seattle only got there early because some local flu researchers disobeyed their own IRB rules and tested cases for the virus without approval.
California seems to have gotten the lockdown about as early as was practical and has done much better than NYC, so they're actually doing well, all things considered.