The Stamp Smarter US "All Stamp Finder" has had two updates.
First, the 2019 stamps have been added; the database now has every stamp from 1847 through 2019 (including many back of book). This brings the total US stamps to almost 10,000; I think this is one of the largest, most detailed online listings of US stamps. http://stampsmarter.com/1847usa/ALLIdentifier.html
Second, due to a nice contribution from community member Swscfdc87
, the US database now also includes a new field named 'Series'. She was kind enough to send me her spreadsheet with US stamps 'series' descriptions and I have updated the Stamp Smarter database to included these. This is a great feature for anyone who wants to quickly see all US stamp filtered by topic. For example, you can quickly see all the US 'Loony Tunes' stamps, or the Kwanzaa stamps, etc. You can give this a try here http://stampsmarter.com/1847usa/ALLIdentifier.html
A big thank you to Swscfdc87
for sharing her work with the hobby.