Use LSEG Workspace to search by identifier or screen using the Search Tools option by selecting Bonds then US Municipal Bonds as the universe. It includes price history, yields, ratings and notes/disclosures, as well as other descriptive information, e.g. issuance and redemption details.

Use Moodys.com.

Municipals are a market sector in Bloomberg (see access details); click the yellow MUNI key (F6) and hit it Enter/GO for the top level menu. Also, use the function STGO for state issued bonds.

Use EMMA (Electronic Municipal Market Access) from MSRB (Mutual Securities Rulemaking Board).

Use MSRB in WRDS (see access details) for price, yield, and interest rate of municipal bonds as well as historical information and other bond characteristics.

Mergent Bond Record is available in Mergent Archives.