Finegan is born November 17, 1814 at Clones, County Monaghan. He comes to Florida in the 1830s, first establishing a sawmill at Jacksonville and later a law practice at Fernandina Beach. At the latter place, he becomes the business partner of David Levy Yulee and begins construction of the Florida Railroad to speed transportation of goods and people from the new state’s east coast to the Gulf of Mexico.
By the outbreak of the American Civil War, Finegan has built his family a forty-room mansion in Fernandina Beach at the site of the modern Atlantic Elementary School. At Florida’s secession convention, Finegan represents Nassau County alongside James Graham Cooper.
In April 1862, Finegan assumes command of Middle and East Florida from Brigadier General James H. Trapier. Soon thereafter, he suffers some embarrassment surrounding the wreck of the blockade runner Kate at Mosquito Inlet. Her cargo of rifles, ammunition, medical supplies, blankets, and shoes is plundered by civilians. Eventually, most of the rifles are found, but the other supplies are never recovered.
In 1863, Finegan complains of the large quantity of rum making its way from the West Indies into Florida. Smugglers are buying it in Cuba for a mere seventeen cents per gallon, only to sell it in the blockaded state for twenty-five dollars per gallon. He urges Governor John Milton to confiscate the “vile article” and destroy it before it can impact army and civilian morals.
In February 1864, General P.G.T. Beauregard begins rushing reinforcements to Finegan after Confederate officials become aware of a build-up of Federal troops in the occupied city of Jacksonville. As Florida is a vital supply route and source of beef to the other southern states, they can not allow it to fall completely into Union hands.
On February 20, 1864, Finegan stops a Federal advance from Jacksonville under General Truman Seymour that is intent upon capturing the state capitol at Tallahassee. Their two armies clash at the Battle of Olustee, where Finegan’s men defeat the Union Army and force them to flee back beyond the St. Johns River. Critics have faulted Finegan for failing to exploit his victory by pursuing his retreating enemy, contenting himself by salvaging their arms and ammunition from the battlefield. However, his victory is one rare bright spot in an otherwise gloomy year for the dying Confederacy.
Finegan is relieved of his command over the state troops and replaced by Major General James Patton Anderson. This change in command is necessary as Finegan is ordered to lead the “Florida Brigade” in the Army of Northern Virginia, where he serves effectively until near the end of the war.
Finegan returns to Fernandina Beach after the war to discover his mansion has been seized by the Freedmen’s Bureau for use as an orphanage and school for black children. It took some legal wrangling, but he is eventually able to recover the property. The untimely death of his son Rutledge on April 4, 1871, precipitates a move to Savannah, Georgia. There, Finegan feels at home with the large Irish population and works as a cotton broker.
It is while living in Savannah that Finegan marries his second wife, the widow Lucy C. Alexander, a Tennessee belle. They eventually settle on a large orange grove in Orange County, Florida. Finegan dies on October 29, 1885, at Rutledge, Florida. According to The Florida Times-Union, his death is the result of “severe cold, inducing chills, to which he succumbed after brief illness.” He is buried at the Old City Cemetery in Jacksonville.