During his final debate with Senator Bernie Sanders, Democratic Party presidential nominee Joe Biden vowed, “If I’m elected president my cabinet, my administration will look like the country.” With Biden’s selection of Senator Kamala Harris as his running mate, he has taken an important first step toward representing the diversity of the Democratic Party and the nation.

If Biden wins the election in November, his cabinet will represent an opportunity to rally underrepresented groups and interests around his administration. As Biden considers candidates for these positions past presidents can offer him a helpful road map for creating a successful cabinet. The best cabinets throughout the history of the United States have been filled with competent, engaged and disciplined secretaries who present diverse views and actively disagree with the president.

The historical importance of a diverse cabinet

In 1789, President George Washington set this precedent for effective leadership by selecting men who represented different regions of the country, backgrounds and ideological interests. Secretary of State Thomas Jefferson was a wealthy plantation owner from Virginia, owned hundreds of enslaved people, and brought critical diplomatic expertise to the administration. Secretary of the Treasury Alexander Hamilton was born in the Caribbean, before making his home in New York City and cozying up to the merchant and mercantile elite in cities. Jefferson and Hamilton disagreed on almost everything and Jefferson later described their cabinet meetings as a “cock fight,” evoking the bloody, brutal nature of their disagreements. While Jefferson hated these confrontations, Washington knew that he benefited from having both perspectives and pleaded with Jefferson to stay and provide “the check of [his] opinions in the administration in order to keep things in their proper channel and prevent them from going too far.”

Other presidents were bold enough to follow Washington’s model. In 1861, President Lincoln famously fashioned a “team of rivals” from his Republican Party competition. Lincoln’s cabinet encouraged him to pursue some of the greatest achievements of his presidency because they didn’t always agree. The more strident abolitionist voices in his cabinet, including Secretary of the Treasury Salmon Chase, pushed Lincoln to consider the abolition of slavery earlier than he might have otherwise. Additionally, by picking secretaries from New York, Ohio, and Missouri, as well as three former Democrats, Lincoln encouraged different regions and factions to feel invested and represented in his administration and the Union. Lincoln was less concerned about checking the power of one side, and more focused on demonstrating party unity and hearing from different voices in the Union.