LexisNexis is a library database that allows for multi-state and code searches by topic. Each state code file includes the constitution, the current advanced legislative service, and all the titles of state code. Separate tables of contents allow one to view the hierarchical structure of the code and the desired code section. The municipal code file allows one to search by keyword across all states/cities included.
The American Legal Publishing website allows one to search across and within the municipal code for 30 states (not all cities represented). Some access is fee-based. (There may be an issue with this page loading in Internet Explorer. If you are having trouble, try accessing it with a different browser, like Chrome or Firefox).