From Browning's History of Golf, "An important step towards the uniformity in this matter (scratch standard or the normal performance of its best players) was the invention of the bogey score. In 1890 the late Mr. Hugh Rotherham of the Coventry Club, conceived the idea of a competition in which each competitor would be invited to play a match under handicap against a hypothetical opponent playing perfect golf at every hole... Mr. Rotherham's first job therefore, was to fix what he called the "ground score" of the Whitley Common (course), the score the scratch player would take for each hole playing perfect golf. The first competition agains this "ground score" was played on 13th May 1891, and in the autumn of the same year the Coventry Club presented a silver challenge cup, to be played for annually under the same conditions."
Browning also speaks of a Dr. Thomas Brown, R.N., the honorary secretary of the Great Yarmouth Club, who introduced the "ground score" in that club shortly after learning of Rotherham's competition. It happened that around that time there was a music hall ditty, with a refrain: Hush! Hush! Hush! Here comes the bogey man! Dr. Brown explained the new form of play as competing against this imaginary opponent, the real bogey man.
Bogey man shot bogey score until the original concept of bogey golf evolved to become the same as the modern "par", the score shot on a particular hole by a first class golfer.
Sometimes it's as much a matter of knowing where to find the information as actually knowing the answer. Maybe the most remarkable aspect of this answer in 2010 is that it came from a real book and not off the 'net. Geez! It felt like swinging a hickory shafted mashie!