Nancy Josephine Landon was born on 29 July 1932 in Topeka, Kansas, to Alfred Mossman "Alf" Landon and Theo Cobb Landon. Her father was then winning the first of two terms as Kansas governor and in 1936 became the Republican presidential nominee against Franklin D. Roosevelt. She grew up in Topeka's Potwin neighborhood with brother Jack, graduated from Topeka High School in 1950, earned a B.A. in political science at the University of Kansas in 1954 (Kappa Alpha Theta; All Student Council; Mortar Board), worked briefly as a Hallmark Cards receptionist in Kansas City, and in 1956 received an M.A. in diplomatic history from the University of Michigan. She married John Philip "Phil" Kassebaum in 1955 (Wikipedia and reference biographies; some obituaries say 1956). They settled on a farm in Maize, near Wichita, and raised four children: John, Linda, Richard, and William. She served as vice president of the family radio company Kassebaum Communications, sat on the Maize school board, and worked on Kansas humanities and ethics commissions.
Separated from Phil in 1975 (divorce final March 1979), she spent about a year in Washington as a caseworker for Kansas Senator James B. Pearson, then returned home. When Pearson retired in 1978, she entered a nine-candidate Republican primary as Nancy Landon Kassebaum, winning with under 31 percent, then defeating former Democratic congressman Bill Roy with about 54 percent. She took office on 23 December 1978. Contemporary coverage and later reference works describe her as the first woman elected to a full Senate term without succeeding a spouse in that chamber, and as the first woman to represent Kansas in the Senate. (Margaret Chase Smith of Maine had earlier been elected without a husband who served in the Senate, though he had served in the House; wording should stay careful.)
She won reelection in 1984 and 1990 with roughly three-quarters of the Kansas vote. A moderate, independent Republican in the Landon tradition, she worked across the aisle on foreign and domestic policy: African affairs and the 1986 Comprehensive Anti-Apartheid Act (Congress overrode President Reagan's veto), El Salvador observation and human-rights pressure, aviation product-liability reform important to Kansas manufacturers, and opposition to a constitutional balanced-budget amendment she called a "seemingly simple solution." From 1995 to 1997 she chaired the Senate Committee on Labor and Human Resources, only the second woman to chair a Senate standing committee. With Massachusetts Democrat Ted Kennedy she drove the Health Insurance Portability and Accountability Act (HIPAA, the Kassebaum-Kennedy Act), signed by President Bill Clinton on 21 August 1996, which expanded portability and limited preexisting-condition exclusions for workers changing jobs. Near the end of her service she also helped create the Tallgrass Prairie National Preserve in the Flint Hills, later naming it among her proudest achievements.
She chose not to seek a fourth term. On 7 December 1996 she married former Tennessee Senator and Senate Majority Leader Howard H. Baker Jr. (Rev. John Danforth officiating), the first marriage between a man and a woman who had both served in the Senate. After Baker became U.S. Ambassador to Japan (2001-2005), they lived in Tokyo, then split time between Huntsville, Tennessee, and her Burdick ranch until his death in 2014; she returned permanently to Kansas. Post-Senate roles included boards and commissions on rural health, campaign finance, and bipartisan foreign policy (including Partnership for a Secure America). In later years she broke with her party's Trump-era turn: she called for impeachment after 6 January 2021, endorsed Democratic Governor Laura Kelly, and in 2024 endorsed Kamala Harris for president. In January 2025 she received the Presidential Citizens Medal from President Joe Biden for bipartisan Senate work, especially health care.
She was preceded in death by parents Alf and Theo, brother Jack, half-sister Peggy Mills, children Richard (2008, brain tumor) and Linda (2020, progressive supranuclear palsy), and Howard Baker. She is survived by sons Bill (Jennifer) and John (Sandra), Baker stepchildren, seven grandchildren, and two great-grandchildren. Nancy Kassebaum Baker died on 21 August 2026 in Manhattan, Kansas, aged 94, of natural causes, her son Bill told the Associated Press. The family planned a private memorial and asked gifts for the Capper Foundation and Kansas 4-H Foundation. Resting place details were not made public in sources checked for this profile.