Steve now lives with his three sons: Michael "Mike" the eldest (age 18); Robert "Robbie" the middle son (age 14) who enjoys playing the trumpet, guitar and dating girls; and Richard "Chip" the youngest (age 7) who attends Webster Elementary. Also sharing their home is Steve’s balding father-in-law William Michael Francis Aloysius O'Casey affectionately called "Bub" and a small orphan boy from the King’s County Children’s Home named Ernie Thompson whom Steve later adopts.

Bub got his name because the Douglas boys couldn't pronounce "Grandpa" and hence the Bub moniker emerged. When Bub traveled to Ireland in 1965 for his Aunt Kate‘s 104th birthday [and never returned], Steve invited Bub's brother Uncle Charley O’Casey, a crusty retired merchant marine to live with them and take over Bub's duties as chief cook and housekeeper. Charlie was born in Sandusky, Ohio.

During Steve's younger days, he played second baseman for the Beaver Dam High School baseball team. At the 1931 class senior hop, Steve played a saxophone. His high school girlfriend was Josephine Kringles. In 1938 Steve's Midwest University graduation had the distinction of having only one female student, Heather Marlow whom he saw at his 25th class reunion.

For food, Steve is partial to Italian. He likes to eat at Luigi's Restaurant. To satisfy his sweet tooth, Steve might order up a Lindy Hop Special that consists of 2 scoops of ice cream, a couple of rings of pineapple, chocolate syrup, a lot of whipped cream with a side dish of almonds.

In the fall of 1967, the Douglas family moved to North Hollywood, California. Two years later, Steve married Ernie’s schoolteacher Barbara Harper, a widow with a headstrong, outspoken young daughter named Dodie [her best friend is a doll named Myrtle]. Steve and Barbara honeymooned at the Concha Azul Hotel in Mexico. In 1972, Steve’s look-alike cousin Lord Fergus McBain Douglas, a Scottish nobleman traveled to America in search of a bride. He lived with Steve and family for a time. Throughout all of the Douglas family ups and downs, the one constant was Tramp the dog, the family's faithful canine - a mixed briard breed. Ernie also had a dog. He was named Wilson.

TRIVIA NOTE: MY THREE SONS is the second longest running TV sitcom (outside of THE ADVENTURES OF OZZIE AND HARRIET at 435). It ran for 380 episodes over twelve years. Before Fred MacMurray agreed to star on the series, he negotiated a 65 non-consecutive day shooting schedule in any one season that shot all the scenes in which he needed to appear. Consequently, all episodes were written far in advance and filmed out of sequence. MacMurray would then, for example, tape all the year's scenes set in the living room in one afternoon. The cast would then shoot their scenes around the "missing" MacMurray weeks later and then through the miracle of some tricky editing, the TV viewers never knew that Fred and his fellow actors were talking to each other weeks apart. This technique was dubbed "The MacMurray Method" and was later adopted by other stars like Brian Keith, Henry Fonda and Bill Bixby. The reason why the Bub O'Casey character was replaced by his brother Charlie O'Casey (William Demarest) stemmed from the sad fact that veteran actor William Frawley who played the role of Bub O'Casey was ill. Shortly after leaving the show, he died of a sudden heart attack on March 3, 1966. Consequently, his part on the show had to be recast. The show's script writers used a visit to Ireland to explain Bub's absence from the Douglas family. On November 25, 1977, Fred MacMurray and other cast members resurfaced in the ABC Reunion special "The Partridge Family/My Three Sons Thanksgiving Special." WiIliam Demarest (a.k.a. Uncle Charley) died on December 28, 1983 of a heart attack at the age of 91. Fred MacMurray (a.k.a. Steve Douglas) died of pneumonia on November  5, 1991 at the age of 83.