Short answers, pulled from the story.
The concept of sending humans to Mars with no intention of returning emerged from the Case for Mars VI Workshop in 1996. George Herbert presented a paper titled One Way to Mars during that gathering, laying out early architectural ideas for permanent settlement.
In June 2013, Aldrin promoted a crewed mission to homestead Mars and become a two-planet species. By August 2015, he partnered with the Florida Institute of Technology to present a master plan for NASA calling for astronauts serving a tour of duty of ten years before colonizing Mars by 2040.
Approximately 200,000 applications started the process, with about 2,500 completed enough for consideration. From those applicants, one hundred were chosen initially, with plans to narrow this down to six groups of four before training began in 2016. On the 15th of January 2019, a court decision liquidated the organization, sending it into bankruptcy administration.
The Moon offers no useful analog for Mars due to differences in atmosphere, geology, temperature range, and rotational period. Antarctica, deserts, and chilled vacuum chambers provide better training grounds at lower cost.
Deuterium concentrations five times greater than Earth make Mars potentially profitable for future fusion industries. High wage scales resulting from labor shortages create economic incentives for settlers to remain.