Backgrounds for Fast Simulation e^+ e^- Collider Studies at mathbf{sqrt{s}=91,250,350,500} GeV

Various proposals for a new $e^+ e^-$ collider operating below 1 TeV are now under consideration by the worlwide High Energy Physics community. Among these are the International Linear Collider and the Circular Electron Positron Collider. We describe high statistics Standard Model background simulation samples generated with MG5_aMC@NLO for $e^+e^-$ collider studies at $\sqrt{s}=91,250,350,500$ GeV. Fast detector simulation is performed with Delphes and DSiD, the detector card for the SiD detector. The samples are compared with other simulation samples generated with Whizard.