Names that Peaked in 1946

An medieval English form of Helen, the sensitive but clear-eyed Ellen has swung in and out of style for centuries, often alternating with the parent name. Ellen was the more common in medieval England, until after the Renaissance, when Helen overtook her. In Edith Wharton's The Age of Innocence, set at the end of the nineteenth century, one character wonders why another has not changed her "ugly" given name to something prettier, like Elaine—a statement few would make today.
 Ellen has been the name of two First Ladies—Arthur and Wilson—and is Scarlett O'Hara's mother in Gone with the Wind. These days, it's most strongly associated in the US with comedian and talk show host Ellen DeGeneres.

Ellen

With the advent of Pope Francis, all forms of this ancient and saintly name came up for a fresh look. Along with most other -een and -ine (when pronounced like -een) names for girls, Francine has a dated midcentury Mad Men feel. But its choice for their daughter by modern glamour couple Casey Neistat and Candice Pool, respectively a video star and a jewelry designer, has made Francine chic again.
 Francine was most popular in her native habitat in the 1940's, while in the U.S. she hit her peak in 1950 at Number 224. A contemporary bearer is writer Francine Prose and comic actress Fran Drescher was born Francine. There are also Francines in two animated TV series: Arthur and American Dad.

Francine

Innocent, sincere, and bright-eyed, and as outdated as its mother name, Gertrude. 

Trudy

This variant of Helen is used across Europe, in France, Germany, Lithuania, Poland, and it's native Hungary. Reminiscent of Elena, Leona, Ilaria, Fiona and Lola, it nevertheless remains a rarity in the US.
 
In Finland, it's a Top 50 choice, associated with the word ilo meaning "joy".

Names that Peaked in 1946

Ellen

Francine

Trudy

Ilona