If you ever feel sad about American Transit, just remember Chicago, Philadelphia, DC, New York, and Boston are all American cities with large transit systems and dense neighborhoods
San Francisco was kicked off this list of good American cities for being home to the Tech Industry
Seattle, Pittsburgh, Baltimore, Cleveland, Portland and The Twin Cities are also doing really well and improving their transit and density, but they need to a lot of work still
LA, Miami and Pheonix could get there one day, but they need a lot of work, LA is trying but needs density, and Miami and Pheonix both need to both expand their transit networks and densify, but I think it is possible in both
I have heard good things about the San Diego streetcar, but I haven’t researched it enough or looked at San Diego enough to tell if it’s a dense city or has good service with the trolley