Name endings can define style eras. The names Marlene and Carlene sound like babies of the 1940s, while Marleigh and Carleigh have the touch of the new millennium. But for names ending in -i, the story is more complicated. It’s a tale of three different American eras.

As you can see from this popularity chart, since the start of the 20th Century -i names have gone from rare curiosities to mainstream popularity, in two waves.

Early in the 20th Century -i names were rare for boys and girls alike. Then around the start of World War II, a surge of -i girls began. After another four decades, as that girls’ surge crested, boys’ names started to join the party.

The changing female:male ratio makes for a dramatic bell curve, peaking in 1962 at a ratio of 72 -i girls for every -i boy. (For reference, the yellow line at the bottom represents an even 1:1 ratio.)

This u-turn curve, while accurate, is misleading. What looks like a return to earlier times is actually a revolution. And each of the three sections of the historical curve—flat, peak, and flat again—is its own cultural era of naming.

1900 to WWII: -i is for Immigrants
In the early decades of the 20th Century, classic English naming still dominated, especially among American-born parents. The shape of English names left -i names scarce. In fact, the biblical name Naomi accounted for the majority of American -i babies born, without ever cracking a top-100 name list.

The remaining -i names of the period included a scattering of rarer biblical names, girls’ nicknames, and an impressive variety of names from cultures around the world, brought to America by immigrant parents. After the biblical names Levi and Eli, the next most common boys’ -i names were Hiroshi (Japanese), Henri (French) and Luigi (Italian). The top girls’ -i names included the Finnish names Lempi and Aili. Names like these were seldom adopted by American families of other backgrounds, and most of them disappeared as immigration declined.

WWII to the Reagan Era: -i is for Informal
The mid-century brought an “American girl” explosion, a wave of new -i hits with a casual, carefree attitude and a youthful sound. The top 35 -i names of the middle period were all female, and except for the holdover Naomi every one was 2 syllables. Most significantly, the names were newly configured, homegrown hits that made up a distinctly American style.

The top 3 names, Lori, Vicki and Terri, demonstrate the blueprint. A familiar nickname like Laurie or Vicky, or occasionally a surname like Tracy or word name like Brandy, was updated with an -i spelling. The -i variant was perceived as fresh and female, a perception which some parents leveraged to put a feminine edge on names like Toni, Jeri and Randi. (For a sense of the male counterparts to this all-female -i phase, the five fastest-rising names of 1957 were Mike, Jeff, Tim, Greg and Tom.) With a couple of generations’ distance this whole era of -i names now looks remarkably unified, and like the face of a generation.

Reagan Era to Today: -i is for Impact
The -i style of recent times is defined by the quest to stand out, with previous generations’ name standards as the backdrop. For boys, the -i ending itself achieved that goal since it had always been uncommon. Parents made hits of biblical names like Levi and Malachi, and imports like Giovanni and Nikolai were increasingly chosen by families of diverse ethnic backgrounds. A slew of new African-American -i names for both sexes were built on the model of African names like Imani. Striking words and brand names like Bodhi and Armani also became popular given names.

Notably, the -i choices of this era also made an impact with length, at both extremes. The typical American boy’s name is 2 syllables and 5-6 letters. Not one of the top 9 -i male names of the Impact era fit that mold. Parents went short with names like Kai and Ari, and long with the likes of Giovanni and Malachi.

A Shift in Mindset
The three eras reflect not just different styles, but different naming impulses. In the first era, most parents assumed they would select baby names from a traditional pool, or from their own family trees. Parents of the middle era began to push against the weight and formality of the past, but they weren’t prepared to go too far out on a limb and conformity was still the order of the day. Then in the third, contemporary era, parents rejected the traditional model of a set pool of names and moved toward something more like personal branding.

Put it together and you have a good thumbnail portrait of American name history, and arguably of the evolution of American culture. All through the lens of a single letter.