I was familiar with one of the towns as it went up for sale a bit ago. At the time, it had two residents. It’s down to one as of 2018 – Buford, Wyoming – https://en.wikipedia.org/wiki/Buford,_Wyoming – Wikipedia disagrees about the population of Buford with RD which was published in 2018; it’s only on the RD and Mental Floss lists. I found three articles trying to figure out the smallest populated areas in the United States – https://www.rd.com/list/smallest-towns-america/, https://www.mentalfloss.com/article/502234/smallest-town-each-50-states and https://www.countryliving.com/life/travel/g4651/smallest-town-in-every-state/. The first link includes a few locations where the population is now 0. The second and third links focus on smallest towns in each state.
Note, neither the first or third lists include Hibberts Gore, Maine – https://en.wikipedia.org/wiki/Hibberts_Gore,_Maine population 1. In general, I ignore population towns unless they recently became ghost towns. I haven’t fully compared the Mental Floss and Country Living lists directly, but as Mental Floss includes Hibberts Gore and Country Living doesn’t, there are several differences between the two lists.