They may not play “Hail To The Chief” when you come in the door but make no mistake, you are the commander in chief of your business. Turns out you’re in good company. A number of presidents started their careers with businesses of their own, many with humble beginnings. Take a look at these presidential entrepreneurs and get some advice you can use.

Jimmy Carter – Peanut Farmer

At age 13, he bought five houses at Depression-era prices in Plains, Georgia and rented them to area families. After a seven-year career in the Navy, Carter took over his parents’ 2,500-acre peanut farm. The business was beset by a drought-induced crop failure his first year and netted only $187. He kept the business running by maintaining several credit lines and employing the latest agricultural techniques. In addition, he managed a seed and farm supply warehouse, continuing his father’s practice of buying local farmers’ peanuts, then selling in bulk to big processors.

Advice: “If you fear making anyone mad, then you ultimately probe for the lowest common denominator of human achievement.”

Herbert Hoover – Consultant

After working as an engineering consultant evaluating mines in Australia and China for potential purchase, Hoover started his own successful consulting business. It focused on restructuring near-bankrupt companies internationally and eventually employed over 175,000 workers. He also owned several profitable silver mines in Burma. Influenced by his Quaker upbringing, his business philosophy emphasized the power of the individual and the value of conscientious work. He also applied principles from his engineering background believing scientific expertise led to human progress.

Advice: “Competition is not the only basis of protection to the consumer, but it is the incentive to progress.”

Abraham Lincoln – Merchant, Inventor, Lawyer

In his twenties, Lincoln partnered with another entrepreneur to open a general store. They bought inventory from other stores on credit and tried to resell them. The town where the business was located stopped growing and the business failed only a few months later. He was left with $1,000 debt which he paid back over 17 years. He also patented a mechanical device that lifted boats over sandbars. It was never manufactured. Finally, he started and ran a successful law practice before becoming president.

Advice: “Always bear in mind that your own resolution to succeed, is more important than any other one thing.”

Harry S. Truman – Haberdasher

After investing in lead and zinc mines, Truman partnered with a friend and opened a men’s clothing store in Kansas City, Missouri. The store went nearly bankrupt during the recession that followed World War I. But he persisted. The store ultimately closed after three years. It took him 15 years to pay off his share of the resulting debt. But he established a reputation as a respected businessman.

Advice: ‘I found that the men and women who got to the top were those who did the jobs they had in hand, with everything they had of energy and enthusiasm and hard work.”

George Washington – Farmer, Manufacturer

Washington is sometimes referred to as America’s first entrepreneur. The crops grown at this Mount Vernon estate served as a springboard for several enterprises. He purchased a grist mill to process his wheat crop into his own branded flour. In addition, he operated a 2,250 square-foot whiskey distillery which turned a profit early in the business’ lifecycle. It produced nearly 11,000 gallons making it the largest in the country at that time. While his labor force questionably depended on slaves, his risk taking, careful account keeping and transparency practices are still relevant today.

Advice: “The harder the conflict, the greater the triumph.”

Take a tip from these presidential entrepreneurs as you manage a small business from your own “oval office.” Their resiliency and business savvy offer useful lessons you can apply, even now.