_TT_,
TrumpetMike caught you...we need to all remember that this is an international site. The cornet soloist is still flourishing indeed in the UK!
I'm hardly a historian and the following is filled with holes but mercifully brief (please excuse my randomness).
Consider the changes in musical society over the past 150 years. Many homes not only had a piano in the parlor but also were owned by people who put in the countless hours needed to play them, and play them well. Withought active music making there would be no music in everyday life (shocking, I'm sure, to our recent iPod babies). News of the latest operas from Europe could be found in the larger American newspapers but the only way to hear the latest from Milano or Vienna was via transcription, usually performed by touring wind bands (called "Italian Bands" since they were similar in instrumentation to bandas.
The cornet was a relatively new instrument at the turn of the 20th century. Virtuoso players such as Kryl, Clarke, Levy, and Chambers emerged, but what to play? Nothing had been composed for their new toy, afterall. Most turned to transcribing popular and art music, adding their own astonishing flourishes and variations. Music was heard outdoors, in the park, and in far more intimate concert settings than in Orchestra Hall. It was music for the people, not for the connoisseur.
. . . then King Oliver emerged from New Orleans. A whole new style of American art music was born and we never looked back.
On a related note, check out this old thread (one of the first) on my forum:
http://www.trumpetmaster.com/vb//showthread.php?t=24591 (Chez Cornet)
Best, and I look forward to other comments.
EC