America's Mining Employment Boom
And that's only counting the direct employment in that sector. Add to that the jobs created by the demand from all those newly hired workers. The inflow of all those workers into the state who has benefited the most from the mining boom, North Dakota, has also created a construction boom in that state.
Though not the only factor, the direct and indirect effects of this mining boom is therefore an important factor behind the recent uptick in U.S. growth.