[2] Bigelow began his political career as a reform Democrat, working with William Cullen Bryant in New York.

[3] In 1861, President Abraham Lincoln appointed him American consul in Paris, and Bigelow progressed to Chargé d'Affaires and Envoy Extraordinary and Minister Plenipotentiary to the Court of Napoleon III.

[4] Historian Don H. Doyle writes, "Bigelow was one of Seward's most brilliant appointees, and he soon became a pioneering master of the arts of public diplomacy in Europe".

After leaving this position, he went to Germany, where he lived for three years, through the period of the Franco-Prussian War, and he became a friend of Otto von Bismarck.

Under the influence of Tilden, Bigelow decided to rejoin the Democratic party, accepted its nomination, and was elected Secretary of State of New York, a position he held until 1876.

He carried out Tilden's wishes, over several years, to develop, design, and establish the New York Public Library and served as its first president from May 27, 1895, until his death on December 19, 1911.