Griswold was educated for commercial pursuits, and at the age of seventeen entered the iron and hardware house of Messrs. Hart, Lesley & Warren, in Troy. He remained at the firm for some time living in the family of his uncle, Maj.-Gen. John E. Wool there after engaging in business for himself in banking and iron works creating at the time, one of the largest and most successful establishments in the United States, known as the Albany and Rensselaer Iron and Steel Works, located in Troy. In 1857, Griswold became a large owner of the iron mills of Troy having been granted the U.S.
Bessemer steel process patents important for expanding the Rensselaer Iron and Steel Works business. During the early part of the
Civil War, Griswold built at his personal expense the first iron-clad Ericsson warship, the
USS Monitor to combat the confederate converted frigate the
Merrimac, which was subsequently defeated by the
Monitor in a historic naval battle in 1862. Griswold was later involved in the production of other "Monitor" vessels, including the
Dictator,
Kaatskill,
Lehigh,
Montauk,
Passaic,
Patapsco,
Puritan and
Sangamon. Griswold assisted in raising the
30th New York Volunteer Infantry Regiment,
125th New York Volunteer Infantry Regiment, and
169th New York Volunteer Infantry; and personally raised the
21st New York Cavalry Regiment, the "Griswold Light Cavalry". He was president of the Troy and Lansingburgh Railroad, of the Troy and Cohoes Railroad and of the New Orleans, Mobile and Texas Railroad.
Congress Griswold first received the Democratic nomination for Congress in 1857, but was defeated by
Abram B. Olin. However, he was later elected as a
Democrat to the
38th and as a
Republican to the
39th and
40th United States Congresses, serving from March 4, 1863, to March 3, 1869. While in Congress, he served on the Committee on Naval Affairs and the House Committee on Ways and Means. In
1868, he was the Republican candidate for Governor of New York, but was defeated by Democrat
John Thompson Hoffman. Griswold was interested in education, particularly in the areas of science and technology, and served as a trustee of the
Rensselaer Polytechnic Institute (RPI); he led the reconstruction movement after RPI and parts of Troy were destroyed by the Great Troy Fire of 1862. Griswold was elected a Regent of the
University of the State of New York on April 29, 1869. In 1871, President
Ulysses S. Grant offered the post of
Collector of the Port of New York to Griswold, who declined. He then offered it to
William Orton, who also declined. Griswold and Orton both recommended
Chester A. Arthur; Arthur received the appointment and served until 1878. ==Personal life==