Roosevelt's support of Wilson led to his appointment in March 1913 as Assistant Secretary of the Navy, the second-ranking official in the Navy Department after Secretary Josephus Daniels.
Roosevelt had a lifelong affection for the Navy — he had already collected almost 10,000 naval books and claimed to have read all but one — and was more ardent than Daniels in supporting a large and efficient naval force.
With Wilson's support, Daniels and Roosevelt instituted a merit-based promotion system and made other reforms to extend civilian control over the autonomous departments of the Navy.
Roosevelt oversaw the Navy's civilian employees and earned the respect of union leaders for his fairness in resolving disputes.
Not a single strike occurred during his seven-plus years in the office, during which Roosevelt gained experience in labor issues, government management during wartime, naval issues, and logistics, all valuable areas for future office.

In 1914, Roosevelt made an ill-conceived decision to run for the seat of retiring Republican Senator Elihu Root of New York.
Though Roosevelt won the backing of Treasury Secretary William Gibbs McAdoo and Governor Martin H. Glynn, he faced a formidable opponent in the Tammany-backed James W. Gerard.
He also lacked Wilson's backing, as Wilson needed Tammany's forces to help marshal his legislation and secure his 1916 re-election.
Roosevelt was soundly defeated in the Democratic primary by Gerard, who in turn lost the general election to Republican James Wolcott Wadsworth Jr. Roosevelt learned a valuable lesson, that federal patronage alone, without White House support, could not defeat a strong local organization.
After the election, Roosevelt and the boss of the Tammany Hall machine, Charles Francis Murphy, sought an accommodation with one another and became political allies.

Following his defeat in the Senate primary, Roosevelt refocused on the Navy Department.
World War I broke out in July 1914, with the Central Powers of Germany, Austria-Hungary, and the Ottoman Empire seeking to defeat the Allied Powers of Britain, France, and Russia.
Though he remained publicly supportive of Wilson, Roosevelt sympathized with the Preparedness Movement, whose leaders strongly favored the Allied Powers and called for a military build-up.
The Wilson administration initiated an expansion of the Navy after the sinking of the RMS Lusitania by a German submarine, and Roosevelt helped establish the United States Navy Reserve and the Council of National Defense.
In April 1917, after Germany declared it would engage in unrestricted submarine warfare and attacked several U.S. ships, Wilson asked Congress for a declaration of war.
Congress approved the declaration of war on Germany on April 6.

Roosevelt requested that he be allowed to serve as a naval officer, but Wilson insisted that he continue to serve as Assistant Secretary of the Navy.
For the next year, Roosevelt remained in Washington to coordinate the mobilization, supply, and deployment of naval vessels and personnel.
In the first six months after the U.S. entered the war, the Navy expanded fourfold.
In the summer of 1918, Roosevelt traveled to Europe to inspect naval installations and meet with French and British officials.
In September, he returned to the United States on board the USS Leviathan, a large troop carrier.
On the 11-day voyage, the pandemic influenza virus struck and killed many on board.
Roosevelt became very ill with influenza and a complicating pneumonia, but he recovered by the time the ship landed in New York.
After Germany signed an armistice in November 1918, surrendering and ending the fighting, Daniels and Roosevelt supervised the demobilization of the Navy.
Against the advice of older officers such as Admiral William Benson—who claimed he could not "conceive of any use the fleet will ever have for aviation"—Roosevelt personally ordered the preservation of the Navy's Aviation Division.
With the Wilson administration coming to an end, Roosevelt began planning for his next run for office.
Roosevelt and his associates approached
Roosevelt's support of Wilson led to his appointment in March 1913 as Assistant Secretary of the Navy, the second-ranking official in the Navy Department after Secretary Josephus Daniels. Roosevelt had a lifelong affection for the Navy — he had already collected almost 10,000 naval books and claimed to have read all but one — and was more ardent than Daniels in supporting a large and efficient naval force. With Wilson's support, Daniels and Roosevelt instituted a merit-based promotion system and made other reforms to extend civilian control over the autonomous departments of the Navy. Roosevelt oversaw the Navy's civilian employees and earned the respect of union leaders for his fairness in resolving disputes. Not a single strike occurred during his seven-plus years in the office, during which Roosevelt gained experience in labor issues, government management during wartime, naval issues, and logistics, all valuable areas for future office.
In 1914, Roosevelt made an ill-conceived decision to run for the seat of retiring Republican Senator Elihu Root of New York. Though Roosevelt won the backing of Treasury Secretary William Gibbs McAdoo and Governor Martin H. Glynn, he faced a formidable opponent in the Tammany-backed James W. Gerard. He also lacked Wilson's backing, as Wilson needed Tammany's forces to help marshal his legislation and secure his 1916 re-election. Roosevelt was soundly defeated in the Democratic primary by Gerard, who in turn lost the general election to Republican James Wolcott Wadsworth Jr. Roosevelt learned a valuable lesson, that federal patronage alone, without White House support, could not defeat a strong local organization. After the election, Roosevelt and the boss of the Tammany Hall machine, Charles Francis Murphy, sought an accommodation with one another and became political allies.
Following his defeat in the Senate primary, Roosevelt refocused on the Navy Department. World War I broke out in July 1914, with the Central Powers of Germany, Austria-Hungary, and the Ottoman Empire seeking to defeat the Allied Powers of Britain, France, and Russia. Though he remained publicly supportive of Wilson, Roosevelt sympathized with the Preparedness Movement, whose leaders strongly favored the Allied Powers and called for a military build-up. The Wilson administration initiated an expansion of the Navy after the sinking of the RMS Lusitania by a German submarine, and Roosevelt helped establish the United States Navy Reserve and the Council of National Defense. In April 1917, after Germany declared it would engage in unrestricted submarine warfare and attacked several U.S. ships, Wilson asked Congress for a declaration of war. Congress approved the declaration of war on Germany on April 6.
Roosevelt requested that he be allowed to serve as a naval officer, but Wilson insisted that he continue to serve as Assistant Secretary of the Navy. For the next year, Roosevelt remained in Washington to coordinate the mobilization, supply, and deployment of naval vessels and personnel. In the first six months after the U.S. entered the war, the Navy expanded fourfold. In the summer of 1918, Roosevelt traveled to Europe to inspect naval installations and meet with French and British officials. In September, he returned to the United States on board the USS Leviathan, a large troop carrier. On the 11-day voyage, the pandemic influenza virus struck and killed many on board. Roosevelt became very ill with influenza and a complicating pneumonia, but he recovered by the time the ship landed in New York. After Germany signed an armistice in November 1918, surrendering and ending the fighting, Daniels and Roosevelt supervised the demobilization of the Navy. Against the advice of older officers such as Admiral William Benson—who claimed he could not "conceive of any use the fleet will ever have for aviation"—Roosevelt personally ordered the preservation of the Navy's Aviation Division. With the Wilson administration coming to an end, Roosevelt began planning for his next run for office. Roosevelt and his associates approached
Franklin D. Roosevelt