Joseph Rucker Lamar (October 15, 1857 – January 2, 1916) was an Associate Justice of the United States Supreme Court appointed by President William Howard Taft. A cousin of former associate justice Lucius Lamar, he served from 1911 until his death in 1916.
Born in Ruckersville, Georgia, Lamar was the son of a minister and attended the Richmond Academy and the Martin Institute in Jefferson, Georgia. After graduating from the Penn Lucy School near Baltimore, Maryland, Lamar attended the University of Georgia where he was a member of the Phi Kappa Literary Society before graduating from Bethany College in 1877, where he was a member of Beta Theta Pi. He then completed law school at Washington & Lee University the following year and began practicing law in Augusta, Georgia.
From 1886 to 1889, he served in the Georgia House of Representatives, and then was appointed by the Supreme Court of Georgia in 1893 as a commissioner to prepare a code of laws for the state. Two years later, that code was adopted by the state General Assembly.
On January 1, 1901, Lamar was appointed to fill an unexpired term in the Supreme Court of Georgia, then was re-elected in 1903. He wrote more than 200 opinions before resigning in 1905 to again practice law, defending railroads and many other large corporations.
At the time of his appointment to the Supreme Court, Lamar was only one of three justices ever nominated by a President of the opposite party. That stellar reputation was one reason Lamar, together with Frederick W. Lehmann, was selected in 1914 to represent the United States at the ABC Powers Conference convened to avert a war over the Veracruz Incident.
In 1915, Lamar wrote two short individual opinions in the famed Leo Frank case. He declined to grant a petition for habeas corpus brought by Frank to challenge the fairness of his trial, but subsequently granted a writ of error allowing Frank to bring his claims before the court. The full Court went on to reject Frank's claim in Frank v. Mangum; Lamar voted with the majority but did not write a separate opinion.
That work, coupled with his court duties, may have led to Lamar's failing health during the fall of 1915. Legislation was proposed to allow Lamar to retire with full pay, but his death just months later made the issue a moot point.