In 1955, J. K. Lilly II and Ruth Lilly acquired a second mansion for themselves in the Indianapolis area, Twin Oaks. This home had been built in the Colonial revival style at the behest of department store heir Lyman S. Ayres II and his wife, Isabel, in 1941.
Josiah and Ruth (Brinkmeyer) Lilly intended to move from Oldfields to Twin Oaks and hired architect David V. Burns to make several alterations. Their intention was to bring the exterior of the house in line with European country homes. They also had Burns raise the roof on the west wing, renovate the kitchen, and build a breakfast room with a pepperpot roof.
In 1961, the Lillys built what Josiah K. Lilly II called a “Hobby House” to contain his collections of stamps, coins, and toy soldiers, as well as a painting studio and a reference library. Two years later, they acquired an adjacent property and demolished a Tudor Revival style home in order to add two acres of land to their estate, which brought it to twenty-two acres.
During this time period, the Twin Oaks estate was fully staffed and J. K. Lilly II visited the Hobby House every day. By mid-decade, all of the alterations and additions were complete, yet J. K. Lilly II and Ruth (Brinkmeyer) Lilly opted not to move after all.
In 1965, Ruth (Brinkmeyer) Lilly died. The next year, J. K. Lilly, Jr. died, as well.
Subsequently, in October of 1966, their two children – Ruth Lilly and Josiah K. (“Joe”) Lilly III – gave the twenty-six-acre Oldfields estate to the Art Association of Indianapolis to create the Indianapolis Museum of Art (I.M.A.), as mentioned in Part II. Earlier that year, the A.A.I. trustees learnt the Herron School of Art had lost its accreditation.
The next year, the A.A.I. trustees transferred the Herron School of Art to Indiana University, University of Indiana – Purdue University Indianapolis (U.I.P.U.I.) campus. It is now the Herron School of Art + Design and it is the only professional school of art and design in the state.
In 1967, the A.A.I. also moved its museum component from the Herron Art Institute to the Oldfields. It opened in the Josiah K. Lilly, Jr. mansion as the Lilly Pavilion of Decorative Arts.
The Art Association of Indianapolis changed its name to the Indianapolis Museum of Art in 1969. Over the years, the I.M.A. has built a number of pavilions. In 2002, it re-opened the newly restored Josiah K. Lilly, Jr. mansion as “Oldfields-Lilly House & Gardens.” It is a National Historic Landmark.
According to the I.M.A., “A National Historic Landmark and listed on the National Register of Historic Places, Oldfields–Lilly House & Gardens is an elegant 26-acre estate on the grounds of the IMA. At the heart of Oldfields is Lilly House, the mansion that was once the home of J.K. Lilly Jr., the late Indianapolis businessman, collector, and philanthropist. Lilly House is a historic house museum and has been restored to its 1930s splendor. Percival Gallagher, of the acclaimed landscape architecture firm Olmsted Brothers, designed Oldfields’ magnificent gardens and grounds in the 1920s. Lilly House is closed January through March for seasonal maintenance.”
In 2007, The New Yorker’s Dana Goodyear observed Ruth Lilly “was a delicate girl born into a famous family in a small town.” In 2009, when Ruth Lilly died, Bruce Weber related in The New York Times, “She graduated from Tudor Hall School in Indianapolis and attended Herron School of Art, but she was afflicted with depression from an early age and spent much of her life in and out of institutions.”
When she was twenty-five-years-old, Ruth Lilly wed Guernsey van Riper, Jr., an editor at the publishing house Bobbs-Merrill and author of athlete biographies for children. They had no children of their own and divorced in 1981.
According to Ms. Goodyear, “Ruth spent the forty years they were together in and out of hospitals, undergoing psychiatric treatment. She is so reclusive that sightings have occasioned newspaper stories… For many years, she was afraid to fly, and didn’t leave the country until after she was eighty. An article in the Star credits Prozac, a Lilly drug, with improving her condition.” In her final years, she travelled “once or twice a year, with an entourage of several dozen doctors, nurses, relatives, attendants, and, sometimes, a chef.”
In the 1980s, Ruth Lilly moved to Twin Oaks. She resided there until her death in 2009.
Ms. Goodyear recounted, “Her house, Twin Oaks, which belonged to her father, is in a prosperous neighborhood, a few miles from Oldfields. It is protected by a screen of tall pine trees and a thread of wire fence. Through the bare woods, you can glimpse a whitewashed brick house with blue shutters, and an attending squad car.”
In January of 2011, William and Laura Weaver acquired Twin Oaks from the heirs of Ruth Lilly. Four months later, they signed an agreement with the Indiana Historical Society (I.H.S.) which called for the organization to lease the residence.
For the Weavers, this arrangement preserved the wooded grounds. The I.H.S. uses the mansion as a hospitality center. Indiana Historical Society President & C.E.O. John Herbst also resides there. Out-of-town trustees and speakers can stay in the guest bedrooms. The Weavers paid to refinish the hardwood floors and paint the building.
A Furnishings Committee provided furniture. The I.H.S. Collections department hung twenty-one paintings of Indiana in the mansion.
 Lyman S. Ayres II was the grandson of Lyman S. Ayres (1824-1896) who founded the L.S. Ayres & Company department store in 1872 when he purchased the Trade Palace in Indianapolis. In 1954, Lyman S. Ayres II succeeded his brother, Theodore B. Griffith, as President of the L.S. Ayres & Company. Eight years later, he succeeded Griffith as Chairman of the Board.