After a partial season with the Pittsburgh Pirates in 1897, Tannehill set a career high in both innings pitched (326+2⁄3) and wins (25) in 1898.

As a result, Tannehill jumped to the startup American League franchise the New York Highlanders.

Tannehill still had some good years left, however; he was an important part of the Boston Americans championship team of 1904.

Tannehill was also noted for his strong bat in his 15-year major league career, posting a career .255 batting average (361-for-1414) with 190 runs, 55 doubles, 23 triples, 5 home runs, 142 RBI and 105 bases on balls.

He suffered a stroke on September 16, 1956 at his home in Dayton, Kentucky and died six days later at the age of 82 at Speers Hospital.