We have 13 Federal Judicial Circuits so 13 Justices makes perfect sense. #SCOTUS ranged from 5-10 justices & was set at 9 in 1869. U.S.A. Census: 1870: 38,925,598 2020: 331,449,281. My math is sketchy, but we had less than 12% of citizens we now have when Congress settled on 9 justices in 1869. HarrisWalz2024