It's very debatable whether a genocide ever occurred or if the definition of genocide is applicable. 90 percent of the indigenous people dying as a result of the European influx died as a result of disease their body couldn't fight. Their is also much debate over the actual numbers who died in the various supposed violent genocides varying wildly.  I've read also that the American government as it is known more or less today did make efforts to prevent their deaths. It was often isolated acts of violence. Nonetheless tragic but a genocide? The evidence does not convince me and by the way I'm not even an American. I mean I'm no expert but I'd look into it if i were you.