[1][a] He attended the public schools and Cadiz Academy, then began to study law with an attorney in Carrollton, Ohio.

[1] In the 1850s, Crozier served on Carroll County's board of examiners, which was responsible for reviewing the qualifications of teachers in the public schools and approving them for employment.

[1] In 1861, and Crozier was appointed United States attorney for the district of Kansas by President Abraham Lincoln.

[1] After leaving the bench, he resumed practicing law and also served as cashier and manager of the First National Bank of Leavenworth.

[1] On November 24, 1873, Crozier was appointed to the United States Senate to fill the vacancy caused by the resignation of Alexander Caldwell.