For 40 years, Forbes has been tracking the ups and downs of America's biggest private companies. The ranks, especially at the top, have been surprisingly consistent. Agricultural giant Cargill is No. 1 for the fifth consecutive year, and it's held the top spot for 38 of the 39 years. Another 43 companies have been on the list all four decades including convenience store chain Wawa (No. 21), cleaning products company SC Johnson (No. 38), wine maker Gallo (No.125) and boat parts reseller Crowley Marine (No. 167). Nearly two-thirds of the 200 companies currently in the ranks have been on the list for the past decade.
To qualify, a private company must have estimated revenue of $3 billion or more from the most recent fiscal year. For 85% of list members, that means revenues for calendar 2024. The others have fiscal years that ended as recently as October 2025.