As McKinley’s professional career progressed, so too did his social life blossom as he wooed Ida Saxton, the daughter of a prominent Canton family. They were married on January 25, 1871, in the newly built First Presbyterian Church of Canton, although Ida soon joined her husband's Methodist church.[44] Their first child, Katherine, was born on Christmas Day 1871. A second daughter, Ida, followed in 1873, but died the same year. McKinley’s wife descended into a deep depression at her baby’s death and her health, never robust, grew worse. Two years later, in 1875, Katherine died of typhoid fever. Ida never recovered from her daughters’ deaths; the McKinleys had no more children. Ida McKinley developed epilepsy around the same time and thereafter disliked her husband's leaving her side. He remained a devoted husband and tended to his wife’s medical and emotional needs for the rest of his life.
Ida insisted that McKinley continue his increasingly successful career in law and politics. He attended the state Republican convention that nominated Hayes for a third term as governor in 1875, and campaigned again for his old friend in the election that fall. The next year, McKinley undertook a high-profile case defending a group of coal miners arrested for rioting after a clash with strikebreakers. Lynch, McKinley's opponent in the 1871 election, and his partner, William R. Day, were the opposing counsel, and the mine owners included Mark Hanna, a Cleveland businessman. Taking the case pro bono, he was successful in getting all but one of the miners acquitted. The case raised McKinley’s standing among laborers, a crucial part of the Stark County electorate, and also introduced him to Hanna, who would become his strongest backer in years to come.