Remembering Jackie Kennedy's 'Enormous Style with Great Simplicity' and the Man Behind Her Looks

The most recent edition of the White House History Quarterly, published by the White House Historical Association, celebrates the former first lady with a feature on "The Jackie Look" by Haley M. Rivero featuring many archival photographs. The piece delves into the life of Oleg Cassini — the former Russian count turned designer — who served as official dresser for Jackie during her time in the White House (and also claimed to be the creator of Grace Kelly's look). Cassini has since gone down in history as the man behind some of her most memorable fashion moments.

"[Jackie] had enormous style with great simplicity," her sister Lee Radziwill once told PEOPLE. "That’s the way I remember her."

One of Jackie's favorite Cassini designs was first created for a June 1962 foreign ministry reception in Mexico.

For Valentine's Day in 1961, the first lady wore a pink wool suit with an asymetrical collar. She was all smiles while meeting with children who represented the Heart Fund.

Cassini often created dresses with "extended shoulders and A-line skirts" for Jackie's daytime outfits. Here, she wore the design while greeting guests in the Red Room.

During her trip to India in March 1962, Jackie visited the Taj Mahal. As he did for many of her trips, Cassini made sure to mirror the local culture while designing her sheath dress with its blue and green pattern.

Jackie sported an elegant red daytime sheath while meeting visitors in the Blue Room.

The president and first lady attended a ceremony at the State Department. For the occasion, Jackie donned a green coat and hat with white gloves.

Wearing a white gown with a green silk cummberbund, Jackie wanted to create a "romantic antebellum look" for a state dinner honoring the president of Pakistan and his wife in July 1961.

A state dinner was held in honor of Mohammad Reza Pahlavi, the shah of Iran, and his wife in April 1962. To celebrate, Cassini and Jackie decided she would wear a gown made of pink and white dupioni silk.

The designer specifically chose vivid yellow for Jackie's silk crepe tunic and skirt ensemble so she'd stand out while mingling with diplomats in the White House in May 1962.

In May 1962, the White House held a state dinner for the president of the Republic of the Ivory Coast. The first lady stunned in a "strapless white tulle gown embroidered with rhinestones and trimmed in gray velvet," Rivero writes in White House History Quarterly.

"Pearls are always appropriate," Jackie famously said. Here she's pictured laughing while a young John F. Kennedy Jr. plays with her necklace in 1962.

One of Jackie and Oleg's favorite designs was this evening dress in "mauve silk chiffon embroidered with hand-sewn crystal beads," Rivero writes.

The first lady wore it for a state dinner in honor of India's president, Sarvepalli Radhakrishnan, in June 1963.