When did jazz get to England?

Not exactly certain but some time in the 1920's. In that decade the ODJB, the popular white New Orleans band, did a tour in the U.K. As they were the first jazz band to record, it's likely that their records, that had had been released in the U.K., led to their being asked to tour. Subsequently, many jazz bands formed in the U.K. to play the "new" music.