The history of the United States public debt started with federal government debt incurred during the American Revolutionary War by the first U.S treasurer, Michael Hillegas, after the country's formation in 1776. The United States has continuously had a fluctuating public debt since then, except for about a year during 1835–1836. To allow comparisons over the years, public debt is often expressed as a ratio to gross domestic product (GDP). Historically, the United States public debt as a share of GDP has increased during wars and recessions, and subsequently declined.