William Drury Deupree was a resident of Pickens County Alabama prior to the war (as late as 1858), explaining why he went there to raise his company.
I'm not so sure that the cavalrymen under his command were as happy and content as the article/obit would have us believe. Many of his men "deserted" to the 7th Alabama Cavalry. However, the unhappiness was likely not related to the captain, but rather to the commanding general. A letter home from Charles H. Keating indicates that the men were extremely dissatisfied with the general that had commanded them at LaFayette, Gen. Pillow. The Captain of Company D (Deupree) was himself trying to resign, and a “heap” of the men were refusing to fight under this General, ever again, according to the letter.
I'm also not so sure about Capt. Deupree raising the company. The information that I have states that S.N. Furgusen, Captain of the company for a few days until election of Deupree, recruited this company in Summer 1863 (simultaneously with recruiting the the 7th Ala. Cav., Co. I which explains why the "deserters" went to the 7th Ala. Cav.) Maybe Deupree did pay for equipping the men.