Spencer Research Library has recently digitized a collection of its Central American broadsides. This digital collection features broadsides from the library's William J. Griffith Collection of Guatemala and Central America. Dating from the 1820s to 1922, these single-sheet publications are primarily Guatemalan, with a smaller number from Honduras, Costa Rica, El Salvador, and Nicaragua. Many pertain to national and local politics and include election materials, political manifestos, and government pronouncements. Additional broadsides address religion, literature and entertainment, education, and lotteries.
The collection is available at https://lib.ku.edu/broadsides
Haven't found what you need at Spencer? Listed below are some online digitized primary sources from other institutions. This page comes from Betsaida Reyes' very helpful Colonial Studies LibGuide.