Short answers, pulled from the story.
The United States Postal Service traces back to the Post Office founded by the Second Continental Congress in Philadelphia on the 26th of July 1775. The modern independent agency itself began operating in 1971, when the Postal Reorganization Act replaced the cabinet-level Post Office Department.
Benjamin Franklin was appointed the first postmaster general in 1775. He had already held a similar position serving the American colonies under British rule.
As of the 29th of March 2024, the United States Postal Service had 525,377 career employees and 114,623 pre-career employees.
The United States Postal Service's monopoly comes from Article I, Section 8, Clause 7 of the Constitution, which lets Congress establish post offices and post roads. That authority has been interpreted as a monopoly over ordinary first-class residential mail, enforced through the Private Express Statutes and the mailbox rule.
The Postal Service Reform Act, signed into law on the 6th of April 2022, forgave $57 billion in Postal Service debt. It also ended the requirement that the USPS prefund retiree healthcare benefits.
Postmaster General Louis DeJoy, appointed in May 2020, has led the push to add 66,000 electric vehicles to the USPS fleet by 2028. The effort is partly funded by $3 billion from the Inflation Reduction Act of 2022.