After earning her M.A. degree, Smith was a planning analyst for Enviro-Med, Inc. in Washington, D.C., and La Jolla, California from 1973 to 1974. She then was a research associate for the National Academy of Science, Institute of Medicine in Washington, D.C. from 1974 to 1977. After she graduated from law school, Smith served as a law clerk in private practice in Norfolk, Virginia. She then served as a law clerk for Judge J. Calvitt Clarke, Jr. of the United States District Court for the Eastern District of Virginia from 1979 to 1980. She was again in the private practice of law at a large firm in Norfolk from 1980 to 1985. Before being appointed a federal district judge, she was a United States Magistrate for the Eastern District of Virginia from 1985 to 1989.
Federal judicial service
On August 4, 1989, President George H. W. Bush nominated Smith for appointment as a United States District Judge of the United States District Court for the Eastern District of Virginia to a seat vacated by Judge D. Dortch Warriner. The United States Senate confirmed Smith's appointment on October 24, 1989, and she received her commission on October 25, 1989. She was the first female federal judge in Virginia. Smith served as Chief Judge for the Eastern District of Virginia and from December 4, 2011 until December 4, 2018. Smith assumed senior status on August 1, 2019.
Titanic artifacts decision
Premier Exhibitions Inc., the parent company of RMS Titanic Inc., the company that salvaged the artifacts from the wrecked ship RMS Titanic on the ocean floor, asked Judge Smith to award it sole title to the artifacts with covenants to preserve them forever. On August 15, 2011, Judge Smith granted title to thousands of artifacts from the Titanic to RMS Titanic Inc., subject to a detailed list of conditions concerning preservation of the items. The artifacts can be sold only to a company that would abide by the lengthy list of conditions and restrictions. RMS Titanic Inc., can profit from the artifacts through exhibiting them.
Just a few days before her decision in the Titanic artifacts case, Judge Smith upheld the validity of Pfizer Inc.'s patent for the erectile dysfunction pill Viagra. The decision blocked Israeli firm Teva Pharmaceutical Industries Ltd., a manufacturer of generic drugs, from marketing a generic version until 2019. Teva had argued that the Pfizer patent was invalid and unenforceable. Among reasons for her decision, Judge Smith found there was no convincing evidence to support Teva's claim that Pfizer intentionally withheld documents from the U.S. Patent and Trademark Office.
Civic work
In addition to her professional work, Judge Smith has devoted much time to work with civic groups, professional associations, charities and educational institutions, including a term as President of the Alumni Association of The College of William and Mary. Judge Smith was a founding member of the I'Anson - Hoffman American Inn of Court, which "was established by charter on May 1, 1987, in Norfolk, Virginia, as part of a nationwide movement to emulate the British Inns of Court, for the purpose of promoting the goals of excellence, civility, professionalism and ethics in the legal profession" and was president of the organization between 1989 and 1991. She was a member of the Federal Judges Association's board of directors and the United States Judicial Conference Committee on Technology. She also was the president of the Norfolk Academy Board of Trustees between 2002 and 2005 and a trustee of the school, a private elementary and secondary school in Norfolk, Virginia, for eighteen years. United States Chief JusticeJohn Roberts appointed Smith to the United States Judicial Conference Codes of Conduct Committee, and she was serving in this capacity in 2011.