He died at his home in 1915; his publications include a lifelong journal, a history of the Spanish–American War, and a verse translation of Virgil's Aeneid.

He received his primary education at Hebron Academy until attending Harvard University where he graduated Phi Beta Kappa in 1857.

[9] His early politics was somewhat independent: he supported the reformist Republican Benjamin Butler for governor in 1871, but received an unsolicited Democratic nomination later that year for a seat in the Massachusetts House of Representatives.

[12] He widened his reform views to the national stage by supporting Benjamin Bristow in his unsuccessful bid for the Republican presidential nomination.

[15] The Democratic opposition was divided by Benjamin Butler's return to that party, and the Republican ticket won the general election.

[16] Long capitalized on Talbot's avoidance of public ceremonies to maintain a high profile despite his post's relative unimportance.

In 1879, Long was easily nominated for governor when Talbot announced he would not run for reelection, despite a lack of support from the party leadership.

[16][17] Long was criticized for his lack of Civil War service and attacked for his diversions from the party line, but won a comfortable victory.

Long re-organized the state government, disputed a statewide law regarding the death penalty, and cut taxes on mortgages in addition to local shipping.

Along with Massachusetts senators Henry L. Dawes and George F. Hoar, he formulated a strategy for the Half-Breeds in the 1880 United States presidential election.

[24] Ultimately, the devised strategy was to push for staunch Half-Breed Vermont senator George F. Edmunds at the Republican National Convention to avoid nominating either Ulysses S. Grant, a favorite of the opposing congressional Stalwarts, or Blaine faction leader James G. Blaine, both of whom opposed civil service reform.

[24] A last-minute maneuvering between the Half-Breeds and supporters of Blaine led to the nomination of dark horse candidate James A. Garfield,[24] who went on to win the general election.

Lodge had been elected to the Senate, dominated the Republican Party in Massachusetts, and had expected to have a say in choosing a cabinet nominee in return for his support of McKinley.

)[36] Lodge compensated for the setback by helping secure the position of Assistant Secretary for Theodore Roosevelt, a brash and aggressive New Yorker.

[2] Roosevelt, on the other hand, sought ways to spur Long into action, writing "I only wish that I could poison his mind so as to make him a shade more truculent in international matters".

[38] He also chafed against Long's policy of deferring much of the department's work to its permanent bureau chiefs, which resulted in constraints on the flow of information the administration received.

[39] Long was somewhat proud of the fact that he knew little of the detail of naval affairs, commenting that he was "a civilian who does not know the stem from the stern of a ship".

[42] By early February 1898, tensions had reached crisis proportions, and Long was compelled to begin drawing up plans for war.

[43] The loss of the Maine highlighted to the administration the nation's shortage of modern warships, setting off a scramble for the acquisition of more ships.

[49][50][51] He also directed naval resources into threatening postures against mainland Spain to encourage the Spanish recall of a fleet destined for the Philippines.

[54] The matter was also caught up in branch rivalry with the War Department, which objected to the Navy's establishment of a permanent base there that was not under its authority.

[55] Long was promoted as a potential vice presidential candidate by the Massachusetts delegation to the 1900 Republican National Convention, and was a personal favorite of McKinley's for the position.

Second, an inquiry into the actions of Admiral Winfield Scott Schley around the July 1898 Battle of Santiago de Cuba had resulted in a significant amount of criticism of Long's role in the war.

[58] These matters drove Long into a depression, and the situation was further exacerbated when Roosevelt squabbled with him over the beginning of the war, and then made newsworthy overrides of some of his decisions.

[59] Historian Wendell Garrett notes that Roosevelt took a great personal interest in the Navy, and had difficulty working with subsequent secretaries.

[62] He continued to advocate for women's suffrage, and served on the boards of several private schools, include his alma mater, Hebron Academy.