Complex sentence: The fire convinced the British to put the city under martial law rather than returning it to civilian authorities, but crime and poor sanitation were persistent problems during the British occupation, which did not end until the city was evacuated in November 1783.
Split into simpler sentences: The fire convinced the British to put the city under martial law rather than returning it to civilian authorities. Crime and poor sanitation were persistent problems during the British occupation, which did not end until the city was evacuated in November 1783.