New and threatened tariffs. Expiring tax breaks. Tighter lending rules at the Small Business Administration (SBA). Small business owners face lots of challenges and uncertainty these days.

But then, starting and running a small business has always been tough. And yet, small businesses remain the mainstay of the U.S. economy, creating jobs, millionaires, and in some cases, big companies and billionaires. Diane Hendricks, #1 on Forbes’ new list of America’s Richest Self-Made Women, with a net worth of $22.5 billion, started a roofing supply business with her late husband, Ken, in Wisconsin in 1982. Under her watch, ABC Supply, which she owns and has chaired since Ken’s death in 2007, has grown to more than 900 branch locations and $20 billion in sales. Peter Cancro started making sandwiches at a Jersey Shore sandwich shop in 1971 at the age of 14, bought out the owner before his high school graduation, and built Jersey Mike’s into a chain with more than 3,000 locations, before finally selling a majority stake this year to private equity firm Blackstone. He’s

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