George Michael Decker Hahn (November 24, 1830 – March 15, 1886), was an attorney, politician, publisher and planter in New Orleans, Louisiana.

Hahn was active as a publisher and editor, owning and operating three newspapers in succession that supported the Republican Party, its program, and its candidates in the state.

Hahn continued to be politically active, being elected to Congress from Louisiana's 2nd congressional district in 1884 with a strong majority.

[3][7] With his widowed mother and four older siblings, Hahn immigrated as a child to the United States, arriving in New York City.

Benjamin Franklin Flanders and Thomas Jefferson Durant, prominent Unionists, opposed the moderate plan called for by General Banks.

Hahn purchased a pro-slavery newspaper, the New Orleans True Delta, and used it to promote moderate Unionism supporting Banks' plan, including emancipation of slaves.

[4] On March 4, 1864, Hahn was inaugurated as governor of Union-held Louisiana in an elaborate ceremony paid for by General Banks.

Governor Hahn played a leading role in the state constitutional convention of 1864, but he was opposed by Major General Stephen A. Hurlbut, who replaced Banks as commander of the Department of the Gulf.

[13] After President Lincoln was assassinated in April 1865, Congress refused to seat any Representatives or Senators from the former Confederacy until a reconstruction plan could be carried out.

Senator-elect Hahn returned to New Orleans and allied with radical Republicans calling for a convention to revise Louisiana's Constitution of 1864 to include black suffrage.

[5] In 1867, Hahn became editor and manager of the New Orleans Republican newspaper, his platform for opposing President Andrew Johnson's lenient Reconstruction program.

He was elected as Chairman of the Judiciary Committee and Speaker of the Louisiana House of Representatives amid the Wheeler Compromise.

In 1884, Hahn was elected to Congress as the Republican candidate from Louisiana's 2nd congressional district – a race that he won handily by 3,000 votes.

[8] Serving as the only Republican Congressman from Louisiana, Hahn died on March 15, 1886, in his room at the Willard Hotel in Washington, D.C.