Over the last 10 years, more than 250 drivers have joined the starting grid for a Formula 4 United States Championship (F4 U.S.) race, with many using the series as a launching pad to the next stage of their careers. Some have progressed through Formula Regional Americas Championship (FR Americas), while others have advanced to the highest levels of motorsport, including the INDYCAR Series, FIA Formula 2, F1 Academy, IMSA, NASCAR and beyond.
The Racing America Formula Ladder has established itself as one of North America's premier development pathways for aspiring professional racecar drivers. Here are some of the most notable graduates from F4 U.S.'s first 10 seasons:
Kyle Kirkwood:
The first driver to capture back-to-back championships in F4 U.S. and FR Americas, Kyle Kirkwood has been part of the Racing America Formula Ladder story since day one. At just 17 years old, he lined up on the starting grid for the inaugural F4 U.S. race at Mid-Ohio Sports Car Course in 2016. He finished third in the championship that season and returned the following year to claim the title with eight victories. In 2018, Kirkwood stepped up to FR Americas for the series’ inaugural season and delivered one of the most dominant campaigns in championship history, winning 15 of 17 races. His rapid ascent continued through the open-wheel ranks, capturing a championship at every level on his way to INDYCAR. After winning the INDY NXT title in 2021, Kirkwood earned a full-time INDYCAR ride for 2022, becoming the first F4 U.S. graduate to reach the pinnacle of American open-wheel racing.
To date, Kirkwood has competed in 79 INDYCAR races. The Jupiter, Fla., native has six wins, three poles, 19 top-five finishes, 41 top 10s, and has led 396 laps.
Christian Rasmussen:
Moving from his native Denmark to the United States to continue his motorsports career, Christian Rasmussen moved up to F4 U.S. in 2018 after competing in the F4 Danish Championship the previous season. With five wins and eight podiums across 17 starts, Rasmussen finished as the third-place champion that season, but more importantly he started on a trajectory that led all the way to INDYCAR. Earning the 2023 INDY NXT title, Rasmussen contested a partial INDYCAR season in 2024 before his first full-time opportunity in 2025.
Over the last three seasons, Rasmussen has tallied 42 INDYCAR starts, but the highlight has been his first-career win, which he clinched at The Milwaukee Mile in 2025.
Noel León:
It didn’t take long for Noel León to prove himself as an international sensation. After taking the 2019 NACAM Formula 4 Championship, León joined the 2021 F4 U.S. championship. A consistent figure on the podium, the then-16-year-old racer collected the championship title and the FIA Super License Points that accompanied it. The next season, he moved to Europe to continue his progression on the Road to F1. With additional experience gained in FR European Championship by Alpine, León went on to win the Euroformula Championship before graduating to FIA Formula 3 by 2024. Spending back-to-back seasons at that level, León tallied five F3 podiums and a career-best finish of second in both the 2024 Silverstone Sprint Race and Hungaroring Feature Race, before finishing third in the FIA FR World Cup at the 10th Macau Grand Prix.
In 2026, León announced a move to FIA Formula 2 with Campos Racing. His first FIA F2 Sprint Race victory came at Montréal in May, and was followed just two weeks later by a second Sprint Race win at Monaco. More recently, he earned his first FIA F2 Pole, winning qualifying in Spielberg, Austria at Red Bull Ring. With 2026 just past halfway, León ranks fifth in his first rookie F2 season.
Kyffin Simpson:
Before winning the 2021 FR Americas title, Kyffin Simpson got his start in F4 U.S. with two top-10 finishes during the first half of the 2020 season before graduating to FR Americas during the latter half of the year. As a Chip Ganassi Racing Development Driver, Simpson made quick ascent up the motorsports ladder in the years that followed his FR Americas title, reaching INDY NXT by 2022 and INDYCAR by 2024. Along the way, Simpson also tallied the 2023 European Le Mans Series LMP2 title, and was part of the team that ran from last-to-first in the GTD Class at the 2022 Petite Le Mans.
Over the last two years, Simpson has amassed 45 INDYCAR starts, recording four top-five finishes, 10 top 10s and leading 13 laps.
Nolan Siegel:
Another current INDYCAR driver who got his start in F4 U.S., Nolan Siegel spent the 2019 and 2020 seasons competing part time in the championship. With a career-best finish of sixth at VIRginia International Raceway, Siegel used the foundation he learned in F4 U.S. to progress up the ladder. By 2024, he won the LMP2 Class at the 24 Hours of Le Mans and embarked on his first INDYCAR season. While signed to a part-time contract with Dale Coyne Racing at first, Siegel got a call from Arrow McLaren in June 2024 with an invitation to join their organization.
In total, Siegel has made 39 INDYCAR starts, leading 19 laps and recording five top-10 finishes.
Rising Stars:
Lochie Hughes:
One of the most promising prospects for upcoming INDYCAR opportunities is 2022 F4 U.S. Champion Lochie Hughes, who currently competes for Andretti Global in INDY NXT. Hughes joined F4 U.S. in 2022 after taking a two-year hiatus from motorsports during the COVID-19 pandemic. Competing for the first time outside of his native Australia, Hughes won six races that season and finished on the podium 10 times to lock in the title. Continuing his climb, the Gold Coast native reached INDY NXT by 2025, and has since recorded three victories in the series. With 117 laps led, three poles and 10 podiums to date, Hughes remains poised to move up the ranks whenever the right opportunity comes along.
Chloe Chambers:
Chloe Chambers raced in F4 U.S. in 2021 before progressing to the W Series in 2022. By 2023, she was racing in New Zealand’s Formula Regional Oceania Championship, and became the first female to win and start a race on pole. In 2024, she got called up to F1 Academy to race with MoneyGram and Haas F1 Team, and the following season, she was invited back to race with Red Bull Ford and Campos Racing. Throughout her two-year F1 Academy stint, Chambers recorded three wins and ranked third in the 2025 points standings.
Ava Dobson:
Following in the footsteps of those before her, Ava Dobson currently represents F4 U.S. graduates in F1 Academy. The Wisconsin native made her F4 U.S. debut immediately following her 15th birthday in 2023. After racing stateside, Dobson moved to Europe to compete in GB4 Championship before getting the call to join the F1 Academy. Representing American Express with Hitech TRG, Dobson’s best F1 Academy finish to date is eighth, recorded earlier this month at Silverstone.
F4 U.S. continues its 10th anniversary season in just two weeks at New Jersey Motorsports Park (NJMP). The New Jersey Lottery weekend featuring Racing America with FR Americas, F4 U.S., Ligier Junior Formula Championship and Sportscar Vintage Racing Association will take place July 31-August 2 on NJMP’s Thunderbolt course. Tickets for the event are available now at RacingAmericaTickets.com.
