Born in Cortland County, New York, Letts received a Bachelor of Philosophy degree from Brown University in 1913, a Master of Arts degree from the same institution in 1914, and a Bachelor of Laws from Columbia Law School in 1917.

[1] Letts received a recess appointment from President Calvin Coolidge on June 9, 1927, to a seat on the United States District Court for the District of Rhode Island vacated by Judge Arthur Lewis Brown.

He was nominated to the same position by President Coolidge on December 6, 1927.

He was confirmed by the United States Senate on January 4, 1928, and received his commission the same day.

[1] After his resignation from the federal bench, Letts returned to private practice in Providence from 1935 to 1947.