May 21 (UPI) -- The U.S. Postal Service kicked off a mail delivery program using self-driving trucks on Tuesday.

May 21 (UPI) -- The Government Accountability Office said Tuesday that government reforms have saved $262 billion since 2010, and could save billions more.

May 21 (UPI) -- A significant severe weather outbreak erupted across the central and southern Plains into Tuesday unleashing drenching rain, flash flooding and at least two dozen tornadoes.

Corn and soybean planting data showed a slight improvement in this week's U.S. Department of Agriculture's Crop Progress Report, but planting remains behind schedule in 17 of 18 key states.

May 21 (UPI) -- Pollster Gallup said Tuesday more Americans are confident in the U.S. job market than they've been at any other time in the history of the poll.

May 21 (UPI) -- U.S. F-22 fighter jets intercepted six Russian military planes off the coast of Alaska Monday, the North American Aerospace Defense Command said.

May 21 (UPI) -- More than a year after a teenager killed himself with a loaded gun in Connecticut, Congress will consider a bill requiring guns be stored safely and away from children.

May 21 (UPI) -- More Americans -- nearly 260 million -- will travel the skies this summer than ever before, an aviation trade group said in a study Tuesday.

May 21 (UPI) -- In a circumstance similar to the iconic film Jaws, a great white shark -- one of the most predatory types in the world -- has been detected for the first time in an estuary on the Northeast U.S. coast.

May 21 (UPI) -- The Donegal Country Library confirmed a copy of the Annie M.P. Smithson book "The White Owl" was returned nearly 82 years later.