I'm afraid I don't have the answer for what you're asking, but it's important to note that the appearance of the Secret Service in protecting state officials was not the actual first appearance of the agency. The Secret Service was founded in 1865 as a part of the Department of the Treasury and remained under their auspices until they were moved in 2003 to the Department of Homeland Security, though their functions remained more or less the same. The Secret Service's functions, at its foundation and now, were mainly to investigate and protect financial systems and identity documents, although originally it also carried out many of the functions now performed by the ATF and other agencies. The Secret Service's role as a protection service only began after McKinley's assassination