United States as a company led me to DTCC and Cede and Co.
Basically all stocks are placed in DTCC's subsidiary Cede and Co. Hard to find info on Cede and Co. But so is the owners of DTCC. Essentially all stocks traded both domestic and largely internationally are owned by DTCC under Cede and Co. No company or shareholder or mortgage is owned by anyone. Lots of good info on linked websites from David Williams posts earlier in this bread and 5.