It's correct that CERN is European. It's also correct that a significant portion of its budget comes from the US. It's further true that basically all the teams working the various experiments at the LHC are multi-national, consisting of European, Asian, and North American researchers (at least, there may be African and/or Australians as well). So it's kind of pointless and dumb for any particular nationality to beat their chest and proclaim that the Higgs boson is their discovery. This was a world-wide effort.