In 1942, Lynne joined the United States Army, where he served in the Judge Advocate General's Corps during World War II.
On June 5, 1956, in the Browder v. Gayle case, the District Court ruled 2-1, that bus segregation is unconstitutional under the Equal Protection Clause of the 14th Amendment to the U.S. Constitution.
[5][6] In 1957, in the Baldwin v Morgan case, Judge Lynne refused to order the desegregation of waiting rooms at Birmingham Terminal Station after two black residents were arrested for using the whites-only facilities.
The plaintiffs' attorney, Oscar Adams, sought a summary judgment to desegregate the waiting rooms.
His view was that no law compelled the passengers to observe the signs and, so while their arrest was improper, there was no further action to be taken as this was not legally segregated.
After the case was appealed, the Fifth Circuit overruled Lynne and ordered him to issue a ruling to desegregate the schools.
[10][11] As an added complication, Lynne, as the Chief Judge, imposed a procedural rule that out-of-state attorneys had to associate with a local law firm in order to argue a case in the court.
[12][13] In June 1963, he ordered Governor George Wallace, who had promised to block the entrance doors of the University of Alabama to prevent black students from registering, to allow Vivian Malone Jones and James Hood to enter the university, ending segregation at that institution.