During his tenure as president, Armour and Co. expanded nationwide and overseas, growing from a mid-sized regional meatpacker to the largest food products company in the United States.

Social reformer Jane Addams met personally with Armour to secure a contract which helped the union survive.

[4] The grounds contained ponds stocked with fish, a large herd of deer, stables, an orangerie, and its own power plant.

The mansion itself contained a bowling alley, twenty marble fireplaces, a green panelled room purchased by Mrs. Armour in London, and a direct line to the Chicago Stock Yards.

[5] The historian of Lake Forest Edward Arpee called it "the most pretentious" of all of the colossal housing appearing in the town at the time.

Armour suffered the most[1] when he lost most of his family fortune—at $100 million in stock (about $1.47 billion in 2010 dollars; then the second-largest in the world[4]) in the downturn.

[8] Armour's daughter Lolita married Chicago banker JJ Mitchell in 1921 at the family's estate in Lake Forest.

[10] Amidst Armour's profound financial losses, he lost Mellody Farms, which is now part of the campus of Lake Forest Academy.

As his condition worsened, he was attended by Lord Dawson of Penn, personal physician to King George V. Armour died of heart failure at 4:30 p.m. London time on August 16, 1927.