During 1890s and beyond: Member of law firm of DeRossett, Burnett, & DeRossett; partner in Burnett, DeRossett & Co. dry goods store which was one of the first businesses in Crossville to have a telephone; served as interim County Judge and interim Sheriff; member Lodge 483, Free and Accepted Masons; and a lifelong, staunch Republican.

5 Jan 1901, Chattanooga News article on prominent citizens of Crossville related the following: "Sampson DeRossett, school superinntendent, was born March 23, 1867, in Grassy Cove, Cumberland County, from which place he moved to Athens, Tenn., when quite young. Graduating in the public school there, he entered the University of Harriman and finished the course there in 1895, with the degree of Ph.D. From there he went to Clinton and became a teacher in the municipal school for eight months, and gave up that work to study law. He graduated and came to Crossville to practice, but seeing a business opportunity he became partner with Burnett, and together opened a general merchandise store. He was made school superintendent and served two terms, being elected without an opposing vote. He was married in May, 1896 to miss Myra Suddath, of Rockwood, and has two children, a boy and girl."

During the 1920s and early 1930s, Sampson served as the Postmaster of the US Post Office in Crossville.

Cumberland County celebrated its centenary in 1956, and the Centennial Committee commissioned a book titled, "Cumberland County's First Hundred Years" to commemorate the occasion. Evidently the authors were in a rush to meet their publication deadline and they either lost or ignored the corrections to the DeRossett Family Tree which Sampson, then the oldest living family member, had provided them. When he read the book and saw several errors still there, he refused to participate in most of the Centinnial events and, prominent senior citizen that he was, this caused an uproar.

His obituary with photograph ran on the front page of the Crossville Chronicle with the headline: "S. DeRossett Dies at Home Sat., June 20"