The country is indebted to some unknown and unheralded genius in San Francisco for the underworld character known as the Hoodlum. Time: about 1870.
Attempts to trace the source of the word have persisted almost ever since, but without success.
The first theory, advanced by Bartlett in 1877 on the strength of hearsay evidence, described it as an accidental coinage of a reporter assisted by his paper’s compositor.
A gang of ruffians, the story was, was under the leadership of one Muldoon.
Fearing reprisals, the reporter spelled the name backward, Noodlum. Poor writing led the compositor to mistake the initial N for H; hence, Hoodlum. This account is still often circulated, though there is nothing factual to back it.
Barere and Leland, in their Dictionary of Slang (1889), though admitting uncertainty, thought the word may have been derived from Pidgin English hood lahnt, “very lazy mandarin,” because of the many Chinese in San Francisco, but they exited gracefully from that poor guess through the preface that the word was “probably of Spanish origin.”
The latest theory, and the most tenable in my opinion, was advanced by Dr. J. T. Krumpelmann in 1935 in Modern Language Notes.
On the basis of the large percentage of Germans, many of them Bavarians, in San Francisco in the sixties and seventies, he thought it probable that hoodlum was nothing more than a slight mispronunciation of the dialectal Bavarian hodalump of identical meaning.