An important businessman of Denison was Hiram Brooks, son of Theodore Brooks (1823–1862) and Martha Ramsey Wiseman Brooks (1826–1914). Hiram was born in Boone County, Missouri, on January 22, 1856. During the Civil War, Theodore enlisted as a 1st Lieutenant in the Union Army, serving in Company F, 9th SM Cavalry Regiment, Missouri. He died of wounds on May 8, 1862, when his son Hiram was six years old. There was a younger daughter, too: Florence Brooks (1859–1934).

Listed as a student in Columbia, Cedar, Boone County, Missouri, in the Census of 1870, Hiram in 1880 was a 24-year-old single male "general merchant" in the same location. An important person in the young adulthood of Hiram Brooks was
an extraordinary man who became his brother-in-law, John T. M. Johnston (1856–1930). A profile written around 1901 recounted:

Young Johnston was left an orphan when twelve years of age, and his early life was necessarily one of labor and privation.... At sixteen years of age he became a Christian and determined to acquire an education, with a view to entering the ministry.  To this end he leased twenty acres of land, which he cultivated upon his own account, meantime practicing the most rigid economy...  On return to Ashland, he took employment in a general store.  Two years afterward opportunity presented for the purchase of a mercantile business, and so well established was his reputation for business ability, industry and integrity that it was transferred to him on his paying the sum of $175, the savings of his two years' clerkship, and obliging himself for the remainder of the $6,000 at which it was valued....  He soon admitted into partnership with himself Hiram Brooks, and later O. Harris.  J.W. Johnston and L. Bass, when the enlarged firm established two branch stores in the county, which with the parent house, built up a business aggregating about a quarter of a million dollars annually.  Subsequently he and L. Bass established the Bass-Johnston Banking Company Bank of Ashland, and later the bank of Brooks, Bass & Johnston, Denison, Texas.  After his business enterprises had become firmly established, Mr. Johnston committed their management entirely to his partners, L. Bass, H. Brooks, S.R. Harell, and John S. Harris, and devoted his energies to the purpose he had formed as a youth.  He was now twenty-eight years of age {ca. 1885}, and he entered the Southern Baptist Theological Seminary at Louisville, Kentucky....  He was married October 15, 1879, to Miss Florence Brooks, a highly educated lady and a devoted laborer in church work.  She is a graduate of Stephens College, Columbia, Missouri.  Four children were born of this marriage.
(Howard Louis Conard, ed., Encyclopedia of the History of Missouri: A Compendium of History and Biography for Ready Reference [Southern History Company, 1901]. pp. 3: 460 - 471)

On August 3, 1883, the Missouri Statesman newspaper reported that Hiram Brooks was opening a grocery business in Denison, Texas. Three months later he married Margaret Mellon in Springfield, Missouri, and the newlyweds moved to Texas.

Listed in the 1887-88 Denison City Directory was Brooks & Harris (Hiram Brooks, Overton Harris), groceries, provisions, feed, 210 W Main. Hiram Brooks was living at 1422 South Fannin Avenue.

By 1891, Hiram and his old partner, Overton Harris, had gone separate ways, with Hiram buying out Overton's interest in the grocery business. The 1891 City Directory carried an advertisement reading: "Hiram Brooks, Dealer in Staple and Fancy Groceries. We study to please our customers and sell only the best. We carry in stock everything the trade demands. Our goods are strictly first-class and prices as low as all other dealers. Produce and Feed. No. 210 West Main Street." Hiram was living at 206 West Gandy Street. Meanwhile, Harris had become a partner with John W. Hayes in Hayes & Harris, purveyors of clothing and gents' furnishing goods, at 105 West Main Street. Both Hayes and Harris were rooming at 600 West Woodard Street and taking their meals at the McDougall Hotel.

In 1896, the City Directory recorded the grocery business at the same location, while Hiram now resided at 709 West Woodard Street.

In the next few years, Hiram Brooks let go of the grocery business and became president of the Bank of Brooks, Bass, and Johnston, as described above. By the time of the 1900 Census, Hiram listed his occupation as "banker," and the Brooks family had acquired a fine residence at 515 North Burnett Avenue.

Hiram and Margaret had two sons, Louis and Eugene. They also had a black live-in male servant, Matthew Smith.

The 1901 City Directory carried this listing: "Brooks, Bass & Johnston. Hiram Brooks, president, Denison; Lawrence Bass, Ashland, Mo.; John T. M. Johnston, St. Louis, Mo.; Benjamin M. Seward, cashier; bankers, 331 West Main, corner of North Burnett Avenue." Hiram is described as "President, Bank of Brooks, Bass & Johnston; treasurer, Gate City Hosiery Mill."

Shortly, the bank folded. The City Directory for 1903 listed Hiram Brooks' occupation as "real estate, 228 West Main; residence at 515 North Burnett Ave." Margaret is listed as his wife. By 1907, however, Hiram had joined John B. McDougall in forming the Denison Bank and Trust Company. He continued his real estate business, now at 122 West Main Street.

By 1910, Hiram had returned to the grocery business, opening Hiram Brooks Grocery at 110–112 North Rusk Avenue. Son Louis brooks worked as a clerk in the store for a few years, then became a traveling agent.

Hiram started to slow down, retaining his real estate business but retiring from the grocery store and from banking. In
1920, the Census reported him living in a smaller house at 214 West Gandy Street, still with wife Margaret. 

He died on May 15 of that year and was buried in Calvary Cemetery. Margaret joined him there upon her death on January 15, 1925.

The Hiram Brooks house at 515 North Burnett Avenue, July 2010.

For many years, beginning in 1971, this property housed the Smith Memorial Chapel Mortuary, operated by James E. and Barbara Smith. A chapel was added at the north end of the former residence. This funeral home primarily served Denison's African American population. The 1994 City Directory lists Carolyn Mumphrey as funeral director. As of July 30, 2010, there was a sign in the yard reading "R. A. Pipkins Chapel and Mercy Mansion."