He represented Port de Grave in the Newfoundland House of Assembly from 1859 to 1866 as a Conservative.
He was a major supplier at Brigus and ran a large fishing station at Indian Harbour.
Leamon originally built his home on his property near Makinsons[1] in 1830 but, during the winter of 1833–34, moved the house ten kilometres to Brigus.
[2] He also served as road commissioner, as a member of the school board and as a justice of the peace.
[1] Hawthorne Cottage, his former home, has been designated a Canadian National Historic Site.