Attended th University of Virginia in 1850 & 1851. He was commissioned a second lieutenant in the Virginia militia April 13,1850 and promoted to captain Nov.8,1856. Moved to
Owensville Robertson Co., TX Jan.1858 and September 21 was licensed to practice law there.He had been an ardent Unionist and strongly opposed Virginia's secession. On December 15,1860, he was a leader in Robertson County calling for the immediate secession of Texas.With the outbreak of the Civil War he enlisted July 15,1861 as a private in the "Robertson Shooters" which became Co., C, Fourth Texas Infantry of the famed Hood's Texas Brigade. He was first elected to corporal and then October 16,1861 to regimental commissary officer from August 6,1862,until the Confederate government, abolished the position in August 1863.That month he applied for a mission to return to Texas, and was appointed December 25, 1863 aide -de-camp to the commander of the First Brigade, Second Division, Texas State Troops. On March 12, 1864 , he was promoted to captain of the Texas State Troops and appointed adjutant general of the Fifth Brigade District. He rose to the rank of brigadier general on December 26,1864.In 1866 he became the first oil prospector in Texas; he drilled his first oil well at Saratoga in Hardin Co. In August 1870 helped to incorporate three business enterprises- the Calvert Bridge Company, to build " a safe and substantial bridge" over the Brazos River at Calvert; the Pacific and Great Eastern Railway Company of Texas, to build a rail link between the Red River and Rio Grande; and the Texas Timber and Prairie Railroad Company, to build a railroad between Beaumont and Bremond.In May of that year he also helped charter the Calvert and Belton Railroad. Hammam moved to Calvert in 1871 when the Houston and Texas Central Railroad reached town. Established a successful legal practice in Calvert . Married Ella Virginia Laudermilk July 26,1871 to this union five children were born.