He was elected to the Maryland Senate in 1899, serving out the unexpired term of John Walter Smith.

[1][3][4] He served as chairman of the Democratic State Central Committee of Worcester County for several years.

[3][5] In 1900, Moore was a candidate for the U.S. House of Representatives, but was defeated by William Humphreys Jackson.

[1][5] Moore married and had three children, Mrs. Samuel K Dennis, Mrs. William R. Bishop and John P. Jr.[1] He was a member of the Protestant Episcopal Church.

[1] He was buried at Makemie Memorial Presbyterian Church graveyard in Snow Hill.