Writing in his autobiography The Company I Have Kept Salt stated that, "I have long thought that Moore's chief book, The Universal Kinship, the gist of which is clearly expressed in the title, is the best ever written in the humanitarian cause."
J. Howard Moore came to Salt's attention when he wrote a notice for a book of his, Better-World Philosophy in 1899. Salt and Moore corresponded regularly for years until Moore's untimely death.
In 1923 Henry Salt dedicated his The Story of My Cousins "To the memory of my friend, Howard Moore, author of 'The Universal Kinship.'"
In The Company I Have Kept Salt paid the following tribute to Moore, "I have a theory that we judge best of the reality of friendships in absence; and if this be true, I cannot have been mistaken as to the warmth of my feelings for Howard Moore, for I never saw him in person, though we corresponded regularly for years, and I have still a big packet of his letters which show him to have been no less lovable as a man than he was brilliant as a writer."
In 1992, Centaur republished Moore's The Universal Kinship as part of its Kinship Library. The book is introduced and edited by Charles Magel. Included in the Appendix are four letters from Moore to Henry Salt