he decided to practice in the west, ostensibly to st. paul, minnesota or st. louis, missouri. however, he decided to settle instead in chicago, illinois reportedly because he was "favorably impressed with the advantages of all kinds which the city seemed to afford him." he practiced in the office of hoyne, miller & lewis and then formed a partnership in 1859, known as stark & isham with james l. stark. isham quickly rose to prominence among chicago lawyers. in 1864, isham was elected to the illinois house of representatives as a republican, where he served a two-year term and was a member of the judiciary committee.