A VERY AMERICAN CIVIL WAR
FEBRUARY 15, 1933
PRESIDENT-ELECT FRANKLIN
ROOSEVELT CRITICALLY WOUNDED BY ASSASSIN
MARCH 4, 1933
ROOSEVELT STILL IN A COMA
WHO IS THE PRESIDENT?
MARCH 8, 1933
HEBERT HOOVER RESIGNS AS PRESIDENT, CITES THE ENDING OF HIS TERM AS REASON
MARCH 10, 1933
VICE-PRESIDENT CHARLES CURTIS SWORN IN AS PRESIDENT QUOTE "THIS COUNTRY MUST
HAVE A PRESIDENT TO COMBAT AN ANARCHIST AND COMMUNIST COUP"
MARCH 11, 1933
PRESIDENT CURTIS APPOINTS GENERAL DOUGLAS MACARTHUR AS SUPREME HEAD OF ALL THE UNITED STATES MILITARY
MARCH 12, 1933
VICE-PRESIDENT ELECT CATCUS JACK GARNER SWORN IN AS PRESIDENT IN SAN ANTONIO, TEXAS
MARCH 15, 1933
PRESIDENT-ELECT ROOSEVELT AWAKENS IN NEW YORK CITY AND IS SWORN IN AS PRESIDENT
MARCH 20, 1933 ROOSEVELT SLIPS BACK INTO
COMA, ROOSEVELT ADVISORS MEET WITH NAVY ADMIRALS
MARCH 26, 1933
NAVY BACKS ROOSEVELT AS LEGITIMATE PRESIDENT, NATION IN TURMOIL
APRIL 1, 1933
AMERICAN ARMY TROOPS BATTLE US MARINES FOR CONTROL OF WHITE HOUSE
CONGRESS FLEES WASHINGTON
MARINE MAJOR GENERAL SMEDLEY
BUTLER CLAIMS THAT A GROUP OF BUSINESSMEN APPROACHED HIM BEFORE THE ELECTION TO LEAD A COUP IF ROOSEVELT WON
IS THE COUNTRY IN A CIVIL WAR?
THE REAL WORLD
On February 15th, 1933 Giuseppe Zangara attempted assassinate FDR. He instead fatally wounded Chicago Mayor Anton Cermak. If he had shot FDR (especially if he had badly wounded him) there would have been a constitutional crisis. The U.S. Constitution did not cover what to do when a President, let alone a President-Elect, was unable to perform the duties of the office, but wasn't dead (that change did not happen until the 25th Amendment in 1967).
In 1933 the President wasn't sworn in until March 4th.
FDR had been Assistant Secretary of the Navy from 1913-1920 and was well thought of by the Navy during his period in office (FDR was a died-in-wool Navy buff and collected many items of US Navy memorabilia such as 2 ships logs books from the USS Constituion from 1815). While Assistant Secretary he supported having a bigger navy.
In 1934, Major General Smedley Butler became involved in a controversy known as the Business Plot, when he told a congressional committee that a group of wealthy industrialists were planning a military coup to overthrow Franklin D. Roosevelt. The purported plotters wanted Butler to lead a mass of armed veterans in a march on Washington and then become a dictator.
The Head of the Supreme Court does not have to be the person who swears in the president. It doesn't even have to be a Judge. In 1923, President Coolidge was sworn in as President of the United States, by his father a Notary Public while staying at his father's house in Vermont.
The competition between the Navy and Army for funds and priority is well known. There wasn't a joint chief of staff for the entire United States Military until 1942 (there had been a Joint Board since the Civil War but it had little legal authority).
As far as the actions of Vice-Presidents Curtis and Garner, that's just fiction (I've got to have somebody causing problems, though Garner once said that being vice-president wasn't worth a "Bucket of Warm Piss").
Yes, I am not a big fan of MacArthur, so expect him, and probably Henry Ford to be the chief bad guys in this little exercise.