What sort of map are you after? Is it maps of the terrain itself that you want, the positions of individual buildings, gangways and such like, or is it territory maps?
If it's buildings, you might be able to download architectural plans of buildings - 'modernist' ones might be best - but I scavenge plans from books on archaeology and architecture, guide-books and information leaflets all the time. No end of battles have been fought over St Paul's Cathedral, the City Walls of York, the monastery of Iona, the Guggenheim Museum in Bilbao (I think) and even one of Frank LLoyd Wright's houses... without my players being any the wiser.
If it's territories, just get a map of pretty much any US city and mash it up. If you can get info on voting districts or something like that, draw those in. Something designed by a bureaucrat somewherre is gonna be way
more nonsensical than anything you could do by looking and drawing shapes
I find tracing or just re-drawing - with a pencil - easier than copying and messing about electronically (I do that for a job, maybe that's why I don't like doing it at home!). But, if you like, scan them, use downloads... the world is your unidentified mollusc!