Born in Eufaula, Alabama, Clark attended law school in Georgia and was admitted to the bar there in 1881, beginning in private practice in Newnan.

When his second term ended in 1901, Clark spent four years in private practice before being elected to the U.S. House of Representatives.

In 1908, Clark gave a speech voicing his strong support for a bill to segregate the streetcars in Washington, D.C., during which he praised segregation and espoused numerous racial stereotypes of African Americans which he believed made them inferior to whites, including that God had created them with "low brow, low order of intelligence, and repulsive features", that "The average negro is perfectly happy when he finds himself eating a watermelon or going on a railroad excursion.

", and that while "the [railroad] cars furnished for negro passengers are just as good as those furnished for white passengers" they do not remain that way because "Imagine a nice, new passenger coach, packed with dirty, greasy, filthy negroes, down South, in midsummer, and you can readily understand why that car does not long remain as good, as clean, and as desirable as a similar car occupied exclusively by white travelers."

"[3] His congressional career ended in 1925 when, despite his history as state chairman, he failed to win his party's nomination to run.