In 1912 he was promoted to car service agent for the Arizona Eastern Railway, which was being leased by Southern Pacific.

[16] He won the primary, along with S. W. Purcell and Andrew P. Martin, and in the general election, he was the only one of the three democrats to win a seat in the House.

[23] Buchanan was only one of three members of the first House of Representatives to return for the 2nd Arizona State Legislature, the others being William E. Brooks and W. J.

[24] In 1916 it was initially speculated that Buchanan would run for re-election in the House, however, by July Buchanan had set his sights on the Senate seat being vacated by Mose Drachman, who had resigned due to his appointment as clerk to the Superior Court.

[25][26][27] There were initially three Democrats seeking the nomination for the two Senate seats, but in August the incumbent, Andrew P. Martin dropped out of the race, leaving just Buchanan and John T.

[32][33] Buchanan remained out of politics for several years, until 1926 when he announced his intention to run for Pima County treasurer.

[36][37] Buchanan followed this with a landslide victory over Republican Walter E. Fuller in the November election, getting almost twice as many votes, 1625 to 850.

[40][41][42] In 1930 Buchanan was precluded from running for re-election for county treasurer due to term limits.

[47] Later in the year, in November, Mit Simms, Arizona State Treasurer, appointed Buchanan to be the inheritance tax examiner for Pima County, to fill out the remaining term of Bradford Duncan, who had died.