The U.S. US national debt hit a record $40 trillion, driven by defense, social programs, and interest. Key points and original sources are listed below.

• The U.S. Treasury's latest statement showed total public debt outstanding at $40.047 trillion on Tuesday, with it having more than doubled in less than a decade.S1

• US national debt hit a record $40 trillion, driven by defense, social programs, and interest. This impacts Americans' finances, raising borrowing costs and lowering wages.S2

• Total public debt outstanding stood at $40.05 trillion at the close of business Tuesday, according to data released Wednesday by the Treasury Department.S3