A holder of this position was the highest-ranking official to resign after an investigation by judge Samuel Seabury, great-great-grandson of the bishop. A non-actor Hugh Grant was the youngest ever holder of this elected position, despite living in Oradell. After being offered a bribe to not run for this office, Henry George ran for this office in 1886. An anti-machine candidate for this office was elected on the City Fusion (-5[1])line and ran an anti-crime campaign that involved banning artichokes and dumping (*) slot machines into the river. That holder of this office established the Triborough Bridge Authority, which was led by Robert Moses. For 10 points, the power of Tammany Hall significantly declined after Fiorello LaGuardia was elected to what office? ■END■ (10[1])