3 June 1868–11 Jan. 1923
In 1900 Grimes ran for secretary of state on the Democratic ticket and won at the youthful age of thirty-two. This was his first elective office, although he had been chairman of the executive committee of the Democratic party in his township since he was twenty-one, had served as aide-de-camp to Governor Elias Carr, and had been urged to run for Congress in 1898 but declined. As secretary of state from 1901 to 1923, Grimes classified and catalogued thousands of historical documents, maps, wills, papers, laws, grants, and other papers that had collected for many years in the secretary's office and made them available for use by the public. With land holdings in Pitt, Beaufort, and Wake counties, Grimes never lost his interest in agriculture and its development in the state. He was a member of the State Board of Agriculture (1899–1900); conservative member of the Farmers' Alliance in North Carolina, which he tried to keep out of politics; member of the North Carolina Agricultural Society and of its executive committee; and member of the Farmers Educational and Cooperative Union and of the State Grange. He was one of the organizers of the Tobacco Growers Association of North Carolina. Later, as president of that organization, he was an avowed opponent of the Tobacco Trust.
Grimes's interest in history evinced itself not only in his private collection of rare books on North Carolina but also in his membership in various societies including the North Carolina Historical Commission (for some years, chairman), the North Carolina Society of the Sons of the American Revolution (board of managers, later president), and the American Historical Association. He was also instrumental in the formation of the State Literary and Historical Association and a member of its executive committee, as well as influential in the development of the state's Hall of History. For several years he awarded the Mary Octavia Grimes Memorial, a gold medal, for the best essay by a student in Pitt County on a subject related to the section around that county.
As secretary of state, Grimes was an ex officio member of the Board of Education. He served on the board of trustees of The University of North Carolina and on the board's executive committee. Other memberships included the executive committee of the North Carolina Council of Defense, Scottish Society of America (president, 1918–19), Masons, Knights of Pythias, and Junior Order of United American Mechanics. He was a Democrat and an Episcopalian.
Grimes made many speeches in the fields of agriculture and history—some at the dedication of public monuments. He was the author of numerous pamphlets and broadsides. His Agricultural Resources and Opportunities of the South (1905?) was an interesting promotional tract, while two volumes that he prepared from records in his custody as secretary of state, Abstract of North Carolina Wills (1910) and North Carolina Wills and Inventories (1912), have been of great use to historians and genealogists. His illustrated monograph, History of The Great Seal of the State of North Carolina, went through many editions after its first publication in 1893. As secretary of state he was also responsible for the reprinting of The Natural History of North Carolina by John Brickell, for which he prepared an introductory note.
In 1894, Grimes married Mary Octavia Laughinghouse, the daughter of Captain J.J. Laughinghouse of Pitt County and the granddaughter of Dr. Charles J. O'Hagan. They had one daughter, Helen Elise. Mrs. Grimes died in 1899. In 1904, Grimes married her sister, Elizabeth Forrest Laughinghouse, who bore him three sons: J. Bryan, Jr., Charles O'Hagan, and Alston. Grimes was buried in Oakwood Cemetery, Raleigh.