To counteract the people's love of journeying to worship at the temple of Jerusalem, their new king, Jeroboam turned them to worsening two golden calves: one at his southernmost settlement at Bethel, one at his northermost settlement at Dan.
It is hard for us to see how the golden calves were so attractive to the people. One explanation is the people were reverting to a worship of golden calves in Egypt. Another is that the calf, rather than being seen as a god, was seen only as the pedestal for an invisible almighty being.
It is interesting with the Tribe of Levi not being ready to sanction such aberrations, Jeroboam was forced to set up his own rival priesthood. e