The February 12, 1909 edition of the Rockford (IL) Republic contained a letter from Mrs. David Hunter, whose brother, James H. Gunsolus, had been a guard on Lincoln’s funeral train.
The letter—published on Lincoln’s birthday—disparaged “contemptous comments” made about Mary Lincoln, noting that “the great uncle of [James H. Gunsolus,] on his mother’s side, partly crippled by a fall from a horse, became a fine horticulturist, and during the Lincoln administration served in the White House conservatories.”
According to Mrs. Hunter, “it was a well known fact among White House employees that Mrs. Lincoln, by the desire and gratefulness of the President Lincoln, stood between him and the insolent, insistent would-be bosses, who harried the White House employees and became a general nuisance about the place.”
Mrs. Hunter concluded by saying, “I intend writing a more fully copyrighted article on the above.”
After several years of occasional searching, I have been unable to find an article written by a Mrs. David Hunter on the topic, or anything other than war records relating to a James H. Gunsolus or the identity of his his great-uncle. More information on the family appears to be availaible here.