He received a Bachelor of Science degree from the University of Tennessee in 1969 and was in the United States Army from 1969 to 1971, achieving the rank of Lieutenant.

He was chief judge from 2008 to 2013, managing the third-busiest federal judicial district in the United States.

In April 2018 McCalla decided a case involving an important constitutional challenge to Tennessee's controversial billboard law.

[2] In 2000, several attorneys who practiced before Judge McCalla and in his courtroom filed complaints against him alleging misconduct.

[6] Despite this incident, McCalla's colleagues subsequently elevated him to the role of chief judge where his work helped to make the United States District Court for the Western District of Tennessee one of the more efficient federal courthouses in the country, according to various statistical measurements including time to trial (one of the lowest) and trials completed (the second highest).