Mrs. Thomas's letter of appeal to Mrs. J.T. Gracey, a former missionary, for her assistance in the matter, led Mrs. Gracey to inquire at the Philadelphia Woman's Medical College if a suitable person could be found among the graduates, who would accept a call from the Woman's Union Missionary Society of America to go as a medical missionary to India. Miss Clara A. Swain, M.D., was named as one fitted by both professional acquirements and Christian character for such a position. It required much thought and prayer on Dr. Swain's part before she could signify her acceptance of the call, and during the three months of delay in giving her answer the Woman's Foreign Missionary Society of the Methodist Episcopal Church, of which she was a member, was organized. Naturally she preferred to go under the auspices of her own denomination, and the Union Missionary Society gracefully and generously accepted her decision.
Confident that she was obeying the call of God, she set about her preparations for the long journey before her in a cheerful spirit, answering the demurs of her friends with, "It is God's call. I must go." She was greatly cheered when she found that Miss Isabella Thoburn, whose brother (now Bishop Thoburn) had been some years in India, was to be her traveling companion. They sailed from New York November 3, 1869, and arrived in Bareilly January 20, 1870, during the annual conference of the Methodist Mission.