| June 20, 1910 36 Stat. 557 |
Congress organized Arizona as one judicial district, authorized one judgeship for the U.S. district court, and assigned the district to the Ninth Circuit. The act became effective upon the admission of the State of Arizona on February 14, 1912. |
| September 14, 1922 42 Stat. 837 |
One temporary judgeship authorized. |
| August 19, 1935 49 Stat. 659 |
Temporary judgeship made permanent. |
| May 19, 1961 75 Stat. 80 |
One additional judgeship authorized. |
| March 18, 1966 80 Stat. 75 |
One additional judgeship authorized. |
| June 2, 1970 84 Stat. 294 |
One additional judgeship authorized. |
| October 20, 1978 92 Stat. 1629 |
Three additional judgeships authorized. |
| November 29, 1999 113 Stat. 1501 |
Three additional judgeships authorized. |
| December 21, 2000 114 Stat. 2762 |
One additional judgeship authorized. |
| November 2, 2002 116 Stat. 1758 |
One temporary judgeship authorized. (Judgeship extended by 127 Stat. 418, 128 Stat. 203, 128 Stat. 2352, 129 Stat. 2443, 131 Stat. 347, 132 Stat. 556, 133 Stat. 159, 133 Stat. 2454, 134 Stat. 1401, 136 Stat. 262, 136 Stat 4672, and 138 Stat. 542.) |