Let's say the greatest of the Federalist's, Chief Justice John Marshall himself, lives up to 1849 and dies at the age of 94. The POD is his wife, Mary Willis Ambler Marshall, doesn't die in 1831 and she stays with him about a decade more.
With him lasting through all of Jackson's term and beyond how would history change? Under what President would he retire, would an extra 15 years of Marshall change any nominee's for President, and Presidential elections themselves? Would he retire before his death knowing his mind would start to deteriorate at some point, or would he tough it out until he could no longer do so.