Sadly, the rise of Farnham's career paralleled the disintegration of her marriage. Following several creative disputes with Louis Comfort Tiffany, Paulding Farnham abruptly resigned from Tiffany and Co. in 1908. Paulding spent the next few years working as a sculptor in New York before traveling West on various get-rich-quick prospecting schemes that drained the family finances. In 1914, with three children to support, Sally petitioned for a divorce, which was granted on grounds of desertion a year later. Living up to her personal motto, "to live, to love and in time let go," Sally set out to make the best of the situation.
In 1916, Sally competed against twenty other sculptors to win a highly prized commission from the Venezuelan government to create a heroic monument of Simon Bolivar, the great South American liberator. Despite numerous setbacks and five hard years of work, the monument was a great success when completed. Heralded as the largest bronze ever created by a woman, the monument was dedicated on April 19, 1921 before a crowd of thousands in Central Park. President Warren G. Harding, whose bust Sally would later model, gave the keynote address. Sally later said that the experience was "the greatest day in my life." For her great accomplishment, she was awarded the highest honor bestowed by the Venezuelan government, the Order of the Bust of Bolivar.
The following decade was a busy one for Farnham. Her inner circle read like a who's who of noted personalities of the Twenties. She counted on friends like Alexander Woollcott, Ralph Barton, Neysa McMein, Mary Pickford and Lynn Fontanne. In 1922, Irene Castle saw a work Farnham first exhibited at the 1915 National Academy of Design and asked her to enlarge it in marble for the grave of her husband and dancing partner, Vernon Castle. The work entitled, The End of the Day, is a quiet, yet powerful statement of grief and loss.
Farnham was often applauded for her skill with portraits. She had a keen eye that was able to capture many details that delighted both sitter and critic. Her bust of Marshal Ferdinand Foch would bring her a grateful letter from the military leader exclaiming it to be the best likeness of him ever created.
In 1925, her Father Junipero Serra was dedicated in Los Angeles at the San Fernando Mission. Two years later, Farnham was commissioned to create another war memorial, this time for Fultonville, NY.