[9][5] When George died in 1916 (as the richest man in Nebraska),[10] Sarah decided she wanted a memorial building dedicated to his life and accomplishments, which would reflect their love for the arts.

[5] It would also serve as a gift to the people of Omaha and a way for the Joslyns to give back to the city that had given them so much.

[4][5][6] In 1940, Sarah Joslyn passed away and gave control of the Society of Liberal Arts to the trustees.

[4][5] The decorative panels on the exterior were designed by sculptor John David Brcin, and refer to the peoples of the plains—both the original Native American inhabitants and the later European explorers and settlers.

[4] Several decades after the Memorial building opened to the public, it was running out of space for staff and the growing collection.

[6] With this idea in mind, he wanted to expand the Memorial and construct additional buildings, which would include a science museum and a planetarium.

[6] The $15.95 million budget included modern art acquisitions, visiting show galleries, a cafe, a kitchen, offices, storage space, a security control center, classroom space, and a beautiful glass atrium that connects the new addition to the Memorial building.

[6] In 2008, construction began on the Joslyn Museum Sculpture Gardens, which would better utilize the space received in the 1987 land exchange.

[4][6][14] The gardens opened in the summer of 2009, featuring work from local and national artists as well as a reflecting pool and waterfall.

[16] Announced in 2018, the most recent addition to the Joslyn Art Museum, the Rhonda and Howard Hawks Pavilion, has added 42,000 sq.

[18] This new space includes galleries, classrooms, a new gift shop, and multi-purpose community rooms.

[18] The exterior of the Rhonda and Howard Hawks Pavilion resembles a cloud, reflecting the original theme of the Great Plains.

Nettie Fowler Dietz, wife of a local business owner, donated her personal collection in 1934, and Jessie Barton Christiancy bequested her collection and that of her late father, the industrialist Guy Conger Barton, to the museum.

After Sarah's death, Paul Grummann, who was the director from 1931–1947, and Harold Parsons purchased European art for the Memorial.

[5] When Eugene Kingman took over as director in 1947, he expanded the Greek vase collection as well as art and artifacts from Indigenous cultures.