From the NC Architects entry:
H. (Henri) Colvin Linthicum (1886-1952), the son of architect Hill C. Linthicum (1860-1919), joined in his father's practice as a young man and after his father's death had his own extensive practice in North Carolina. He was the third generation in the building professions: his grandfather, Hill's father, William H. Linthicum (1818-1886), was a builder in Virginia and then in Durham, North Carolina.
H. Colvin Linthicum was born to Hill and Elizabeth Freeborn Linthicum, residents of Henderson, North Carolina, where father and son designed several buildings. By 1904, Hill C. Linthicum had established an office in Durham. In 1912, after completing his architectural education at the University of Pennsylvania, H. Colvin entered his father's office as a draftsman. He had previously studied at the Oak Ridge Military Academy and the Bingham Institute in North Carolina and attended Smithdeal Business College in Richmond, Virginia, before deciding on a career in architecture. In 1915, the two Linthicums were among the first architects in North Carolina to gain their licenses after passage of the licensing act in 1915. H. C. Linthicum's certificate was #23, and Hill C. Linthicum's was #24, both in the group of men granted licenses in 1915 based on their prior professional practice.
In 1918 the younger Linthicum became a full partner in the firm, and he continued the business alone after his father's death in 1919. By 1920 he and his wife, Katherine, were residing in Durham. The firm specialized in school designs in the 1920s and, according to an advertisement in the Raleigh Times in 1925, served as official architect for North Carolina school boards in Alamance, Cumberland, Guilford, Orange, Polk, Sampson, and Stokes counties, where the firm doubtless designed numerous school buildings.
Examples of H. Colvin Linthicum's work in this period include the Renaissance Revival style Erwin Auditorium (1922) and West Durham Southside School (1922), both in Durham. The firm, which continued in business until about 1946, planned Rex Hospital in Raleigh during the 1930s and twenty-two National Guard Armories in eastern North Carolina. Further research is needed to document additional work by this prolific firm.