Marlene Hays and her late husband, businessman Spencer Hays, had already given 187 artworks to the Orsay museum in Paris worth more than €173 million, the biggest donation to a French museum since World War II.
Now Hays, 82, who was widowed in 2017, is giving a further donation of 106 works from mostly post-Impressionist artists including Matisse, Bonnard, Modigliani and the sculptor Camille Claudel.
The latest gift of 40 paintings, 47 works on paper and 19 sculptures brings the Hays' donation to the world's greatest collection of Impressionist art to nearly 300 pieces.
The couple – who used to give each other masterworks for their birthdays – were made commanders of the Legion d'Honneur, one of France's highest honours, for their generosity by former president, Francois Hollande, in 2016.
Spencer Hays said then that their private collection of more than 600 artworks worth an estimated €350 million “would be gifted to the French people for the benefit of art lovers around the world” after their death.
French Culture Minister Franck Riester praised Marlene Hays for her “exceptional gesture… which is a historic enrichment of France's national collection” of late 19th-century and early 20th-century art.
He said Marlene had started collecting US art in the early 1970s before becoming fascinated by the “Nabi” post-Impressionist movement and art that depicted Paris.
The couple built a perfect replica of an 18th-century Paris mansion, the Hotel de Noirmoutier, in Nashville where they lived.
Spencer Hays was a colourful businessman who began his career as a door-to-door book salesman for the Southwestern Company in Texas before rising to become its majority shareholder.
“When Marlene and I grew up in a little town in Gainesville, Texas, even visiting France was far beyond our greatest expectations,” he said when the couple donated the first part of their collection.
“But in 1971 we made our first trip to Paris, and our love affair with this wonderful country began,” he added.