[5] He won the silver medal in the high jump at the 2023 World Athletics Championships.

[6] Harrison attended Columbia high school in Huntsville, Alabama.

[10] On June 27, 2021, Harrison won both the long jump and the high jump at the US National Team Olympic Trials in Eugene, Oregon.

[11] After the 2020 Olympic Trials, Harrison signed with Puma to compete professionally.

In 2023 Harrison won the silver medal at the World Athletics Championships in Budapest, finishing second to reigning Olympic champion Gianmarco Tamberi of Italy on a countback despite clearing the same 2.36 metres height.