When was new madrids last major earthquake?

Earthquakes occur in the New Madrid seismic zone every day. Most of them are so small (magnitudes 0, 1, 2...) that they can't be felt, only recorded by an instrument. The faults in the New Madrid seismic zone are active, producing these small events all the time. If you mean Madrid, Spain, you can do an earthquake search by googling "international seismological centre".