A painter of landscape, cattle, and sheep, C. Morgan McIlhenney received training at the Pennsylvania Academy of the Fine Arts and with Frank Briscoe. He spent several years on a sketching trip in the South Pacific before returning to the United States in 1881 and settling in New York City. He married Ada Ingersoll in 1888 and seems to have experienced a period of success several years later when his Gray Morning (subsequently purchased by Samuel T. Shaw) won the Academy's First Hallgarten Prize. This honor followed upon his election to ANA and his taking of the Evans Prize at the 1892 annual exhibition of the American Water Color Society. By then, he had left Manhattan for residence in Shrub Oak, New York. He exhibited frequently with the American Water Color Society, and his watercolors were also featured in exhibitions at the Macbeth Gallery, New York.
McIlhenney died in New York's Presbyterian Hospital. Noting his early promise, the obituary read into the Academy Minutes lamented that "illness and the pressure of untoward circumstances clouded his life, and brought it to an untimely close in his forty-sixth year." A sale of his work occurred at New York's American Art Galleries the year after his death.