Manton was born in New York, New York. He received a LL.B. from Columbia Law School in 1901. He was in private practice of law in New York City from 1901 to 1916.

Manton was a federal judge to the United States District Court for the Southern District of New York. Manton was nominated by President Woodrow Wilson on August 15, 1916, to a seat vacated by Charles M. Hough. He was confirmed by the United States Senate on August 23, 1916, and received commission the same day. Manton's service was terminated on March 22, 1918, due to appointment to another judicial position.

Manton was a federal judge to the United States Court of Appeals for the Second Circuit. Manton was nominated by Woodrow Wilson on March 12, 1918, to a seat vacated by Alfred Conkling Coxe. He was confirmed by the United States Senate on March 18, 1918, and received commission the same day. Manton's service was terminated on February 7, 1939, due to resignation.

Manton was born in New York, New York. He received a LL.B. from Columbia Law School in 1901. He was in private practice of law in New York City from 1901 to 1916.

Manton was a federal judge to the United States District Court for the Southern District of New York. Manton was nominated by President Woodrow Wilson on August 15, 1916, to a seat vacated by Charles M. Hough. He was confirmed by the United States Senate on August 23, 1916, and received commission the same day. Manton's service was terminated on March 22, 1918, due to appointment to another judicial position.

Manton was a federal judge to the United States Court of Appeals for the Second Circuit. Manton was nominated by Woodrow Wilson on March 12, 1918, to a seat vacated by Alfred Conkling Coxe. He was confirmed by the United States Senate on March 18, 1918, and received commission the same day. Manton's service was terminated on February 7, 1939, due to resignation.