Originally from the small town of Rollingstone, Keller was elected to the House in 1948, serving one term, and, in 1950, opted to run for the Senate seat being vacated by Senator Leonard Dernek of Winona. He was re-elected in 1952, 1956 and 1960, but was unseated by Roger Laufenburger in the 1962 general election. He represented the old District 2, which included all of Winona County.
Keller allied with the Conservative Caucus at a time when the legislature was still officially nonpartisan, although he identified as and was known to be a Republican. While in the Senate, he chaired the General Legislation Committee from 1955 to 1962, and was also a member of the Committee on Committees and the Rules Committee.
Dubbed a "gruff-voiced, cigar chomping, hard-bargaining Senate veteran," Keller was a leader in forming tax policy for the state. He also actively promoted highway safety and, in 1959, introduced a bill that would have required seat belts and padded dash boards in all cars made after 1961. In 1961 alone, he was the chief author of 18 bills calling for new and tougher traffic safety laws. He also served as chairman of a legislative interim study commission formed to analyze and make improvements to the Minnesota Highway Department.
Keller was a farmer in the Rollingstone area for many years. He moved to Winona in 1955, where he worked as a contractor and was active in the local community, being involved with such organizations as the Elks Lodge, the Knights of Columbus, and the Winona Association of Commerce, a predecessor of the chamber of commerce. He was also an executive board member of the Boy Scouts for ten years. He died in Winona in 1972.
Keller's daughter, Pat Kronebusch, was later elected to the Senate, unseating Senator Laufenburger in 1980. After taking office, she received her father's old desk on the Senate floor.
When the Ottoman Empire conquered Libya in 1551 the Turks began migrating to the region, as a consequence, many Turkish soldiers married Arab women and their children were known as the "Kouloughlis" (also referred to as the "Cologhla", "Qulaughli" and "Cologhli").
By 1936 the Turkish community formed 5% of Libya's population, numbering about 35,000, of which 30,000 lived along the Tripolitanian coast.
Today there are still Libyans who regard their ethnicity as Turkish, or acknowledge their descendants to the Turkish soldiers who settled in the area during the Ottoman rule. Indeed, many families in Libya can trace their origins through their surnames. It is very common for families to have surnames that belgong to the region of Turkey that their ancestors migrated from; for example, Tokatl, Eskiehirli, Mulal, and zmirli are very common surnames.