Henry Jacob Hamel (August 10, 1863-March 10, 1938) was born to immigrant Hartman Henry Hamel of Hatzback, Germany and his American-born wife, Anna Maria Wirtz of Louisville, Kentucky. Henry J. Hamel's father, Hartman Henry Hamel (November 5, 1831-October 5, 1911) grew up farming with his father in Hatzback, Germany before immigrating to this area by way of New York; he sailed aboard the vessel Harriett in May 1851, to join his brother in Illinois and in 1853 came to California by overland caravan. Settling in Hangtown (Placerville), he was unsuccessful in mining and took up work freighting between Sacramento and the mining camps. With his marriage to Anna Maria Wirtz on June 29, 1858 in Sacramento City, the couple bore fourteen children, raising nine to maturity:
- George F. (April 13, 1859-May 3, 1923)
- Henry J. (August 10, 1863-March 10, 1938)
- Carrie M. (October 30, 1865-May 27, 1956)
- Fred (December 23, 1867-1934)
- Alma M. (February 24, 1870-August 6, 1959)
- Charlotte E. (September 20, 1871-July 20, 1962)
- William C. (December 19, 1873-February 27, 1952)
- Edward (February 26, 1876-February 2, 1944)
- Elizabeth M. (April 28, 1882-).
In 1862, Hartman Hamel opened a meat market in Placerville and operated it until 1867 when he relocated his family to a 1,200 acre ranch just south of Davisville; this ranch became the center of a large cattle and farming operation. All nine of the couple's surviving children were educated in the Davisville school district.
Henry Jacob married the former Lida O'Dea, a native of New York City who was brought to Davisville in 1866 by her parents, Mr. and Mrs. Patrick O'Dea. Orphaned at 12 years, she lived with the O'Neal and Hayden families until her marriage. Two children were born of this union. George Hartman, now of Woodland, farmed land seven miles west of Davis. In 1920, Henry J. built what is locally known as the H. J. Hamel House (505 2nd Street) for his family — today the building is leased to Coldwell Banker Doug Arnold Real Estate, Inc..
Three children born of George's marriage to Georgia Everett are: Gene H. and Gloria Loraine (Mrs. Carl Bremmer), both of Woodland; and Ruth Elizabeth (Mrs. Fred Greeley), of Fresno. Irma Marie Hamel married Thomas Albert Sparks, Jr., the grandson of Martin V. Sparks, a pioneer of '49, who sold his Davisville ranch for the University Farm. Their children are Henry Alva, Chief of Medicine at Oak Knoll Naval Hospital; Robert Edward, of Martinez; and Charlotte Marie (Mrs. James Hudd Beattie), of Newcastle, California, where Marie Hamel Sparks also lives.