I found this a fairly dated but occasionally interesting read.

They stretch credibility as the city travels immense distances in space… The encounter a planet floating in space where there are no others and a group of floating city “hobos” which barely have enough electricity to maintain flight but have a big beef with their home planet of Earth. The city of New York floats from one situation into another continually evading the police due to their past (and current) indiscretions as they seek the next bit of work. Amalfi leads his flock through various crises with an iron constitution and often brutal, violent hand which is possibly a bit less offensive to the original target audience for this series then it is likely to be to modern readers. In particular we follow the floating city formerly known as “New York” with it's mayor/pilot John Amalfi having been in the position for a good number of hundreds of years (the “Oakies” - as those that inhabit the cities are known - having found a chemical secret to immortality). The book is arranged chronologically with the first “They Shall Have Stars” story setting the technological and political scene for the books that follow the rise and decline of these floating cities. This is a compilation of the classic James Blish “Cities in Flight” series consisting of “They Shall Have Stars”, “A Life for the Stars”, “Earthman, Come Home” and “The Triumph of Time” telling the story of cities on Earth deciding to leave their increasingly repressive society by attaching “Spindizzy” drives to their cities and, literally, lifting their entire city out into space where they offer services for hire to any groups that wish to use them as they drift from place to place.

Blish cities in flight