William Preston Lane, Jr. was born May 12, 1892, the second son of William Preston Lane and Virginia Cartwright Lane. His ancestors were among the earliest and most prominent settlers of the state; one was a proprietary Governor of Maryland (1676-1681). In 1922, he was married to Dorothy Byron. They had two daughters, Dorothy and Jean. Lane received his bachelor's degree in law in 1915 and was admitted to the Maryland Bar in 1916. He immediately entered into partnership with the law firm of Keedy and Lane in Hagerstown, and later, in 1919, became a partner in the firm of Lane, Bushong, and Byron..
Appointed captain in the 1st Maryland Infantry National Guard in 1915, Lane saw service on the Mexican border in 1916. During World War I, he fought with the 115th Infantry and was awarded the Silver Star. Lane was promoted to major and Assistant Division Adjutant of the 29th Division after the war. During World War II, he was involved in the organization of the Maryland State Guard and Maryland Minute Men and served as lieutenant colonel in command of the 8th Battalion.
In 1922, William Preston Lane became president of the Herald-Mail Company, which published two Hagerstown newspapers, the Morning Herald and the Daily Mail. He became vice-president of the Hagerstown Trust Company in 1933, later succeeding his father as president. He also served as director of the W. D. Byron and Sons Tannery, Hagerstown Shoe and Legging Company, and the Washington County Railroad Company.
Lane's political career began in 1928 upon his election to the Board of Education of Washington County. Two years later, during Governor Ritchie's term of office, he was appointed Attorney General for Maryland and while in this position gained a reputation for outspokenness and courage. He won national recognition in 1933 for his anti-lynching campaign, although this caused him to lose favor in the Maryland Democratic organization.
While in temporary retirement, Lane was senior partner in the law firm of Lane and Mish. Also at this time he became a director of the Washington and Berkeley Bridge Company and the Fairchild Aircraft Corp. He served as a delegate to the Democratic National Convention from 1928-1948 and, from 1940 to 1950, was the Democratic National Committeeman for Maryland. In 1944, Lane managed Roosevelt's fourth presidential campaign in Maryland, pitting himself against his political rival U. S. Senator Millard E. Tydings. When Lane, in 1946, sought the nomination for governor, Tydings supported his rival J. Millard Tawes. After a very costly and hard-fought preliminary campaign, he was victorious of Tawes and easily defeated the Republican candidate for governor, Theodore R. McKeldin. Governor Lane then served as chairman of the Southern Governor's Conference in 1947 and 1948.
During his term the original Bay Bridge was begun and completed, and great strides were taken in improving the state's school and hospital systems. Governor Lane also instituted the first state sales tax in spite of bitter opposition. Although this cost him a second term of office, he was vindicated when Maryland ended its next budget year in the strongest fiscal condition it had ever enjoyed.
After retiring from public life in 1951, he continued his various business endeavors. William Preston Lane, Jr. died suddenly of a heart attack on February 7, 1967.