Robert Wenger was born on October 15, 1857 in Wisconsin to Christian Wenger and Ursula (Mueller) Wenger. He grew up in Alma, Buffalo, Wisconsin. His parents emigrated to the US from Switzerland, and his father was a farmer.
In 1883, at the age of 26, Robert was married to Elizabeth Meng. They bought her parents’ farm, and the couple continued residing in Alma for the next several decades. They had six daughters: Mary (b. January 1884), Laura (b. February 1887), Amanda (b. May 1893), Olga (b. January 1895), and Elva (b. March 1897). Robert died on April 9, 1919.