Jini Park’s social media feed blew up last week with news of Andy Kim’s Senate victory. She had voted for his opponent. Yet, scrolling through articles on her phone, Ms. Park was overcome with pride that a child of Korean immigrants, like her, had reached a pinnacle of power in the United States.

Mr. Kim, a New Jersey Democrat, will be the first Korean American to serve in the Senate when he is sworn in later this month. The milestone comes more than a century after the first wave of immigrants from the Korean Peninsula began arriving in the United States and has vaulted the community to a largely unfamiliar position: the spotlight.

California and New York are home to the greatest number of the country’s 1.8 million Korean Americans.

But nowhere is the community’s imprint more clear than in northern New Jersey, where a half-dozen towns in Bergen County have some of the highest percentages of Korean Americans in the nation.

For decades, Korean Americans have followed a well-trod path from New York City, over the George Washington Bridge, into Fort Lee, Ridgefield and Leonia in search of good schools and cheaper housing in New Jersey.