I would think the freedom we have to travel makes this strategy ineffective. It's not like China where they physically locked down Wuhan.

https://www.npr.org/2020/03/26/822049287/read-president-trumps-letter-to-governors-on-new-coronavirus-guidelines

President Trump said in a letter to U.S. governors on Thursday that his administration is working to publish new guidelines for state and local governments to use when making decisions about "maintaining, increasing or relaxing social distancing and other mitigation measures" for the coronavirus epidemic.

Trump said his administration is gathering testing data which will suggest guidelines categorizing counties as "high risk, medium risk or low risk" for the virus. The data will drive "the next phase" of the response, he said.

Trump has indicated that he wants to adjust his 15-day social distancing guidelines so that more parts of the stalled U.S. economy can reopen by April 12. The 15th day of those guidelines is Monday, March 30.