Inventor and proprietor of the Buckeye Bell Foundry/The E.W. Vanduzen Company, Cincinnati, Ohio. Ezra began spelling his last name as "Vanduzen" at some point, although his father, siblings and some of his children continued to spell it as "Van Duzen". It has been suggested that Ezra was rather frugal and may have done this to avoid the extra space required when putting the company name on their bell castings. This theory might be supported by the fact that most of the individual graves in his family plot are unmarked; mostly his family members who died while Ezra was still alive. The family bible of his youngest brother Charles Martin Van Duzen, as well as many signatures in family records (including his son Frank) indicate that the original spelling is "Van Duzen".

Ezra's middle name is "Williams", not "William". A common practice at the time, this name comes from the maiden name of his paternal grandmother Deborah Williams Van Duzen.

Ezra married Anna Eliza Dowd (daughter of Charles Horatio Dowd and Anna Eliza Miles) on 16 Oct 1844 at Cincinnati, Hamilton County, Ohio.

Ezra worked for the G.W. Coffin Company, a bell manufacturer in Cincinnati, Ohio. Ezra and partner C.T. Tift purchased the company from Coffin in 1866 and operated as the Buckeye Bell Foundry/Vanduzen & Tift Company, where they continued making bells and chimes. Upon Tift's death in 1890, Ezra bought Tift's interest in the company from his estate, he continued operating it as the Buckeye Bell Foundry/E.W. Vanduzen Company until his death.

Perhaps his most notable accomplishment was the manufacture of "Big Joe", the largest swinging bell ever cast in the United States. Measuring 7 feet tall and with a diameter of 9 feet, the 17.5 ton bell was hauled by 12 horses up Gilbert Avenue, then down Madison Road to St. Frances de Sales Catholic Church in what is now the East Walnut Hills neighborhood of Cincinnati, Ohio. When it first swung in January 1896, its deafening tone startled the Walnut Hills neighborhood and could be heard for 15 miles. The resultant E sharp produced vibrations said to have shook the houses and buildings below and shattering nearby windows. However, a modern-day bell expert at the Cincinnati-based Verdin Company, foundry of the nearby (Newport, KY) and even larger World Peace Bell (which was cast in France), dismisses damage to window glass inflicted by Big Joe as a local legend with no historical basis. According to them, Big Joe was never swung again because of trembling in the bell tower and crumbing of mortar; the bell was simply too big for its tower.

Ezra died at his Cincinnati home on Reading Road due to complications from old age and bronchitis. He was buried next to his wife in his family plot on March 31, 1911. His daughter Martha took over as president of his bell foundry.