Answer:
Meriwether Lewis and William Clark are best known for their expedition from the Mississippi River to the West Coast and back. The expedition, called the Corps of Discovery, was President Thomas Jefferson's visionary project to explore the American West. It began in May of 1804 and ended in September 1806.
Explanation:
They were all slave states that had remained in the Union and this is what Missouri, Kentucky, Maryland and Delaware had in common during the Civil war. The correct option among all the options that are given in the question is the second option. I hope that this is the answer you were looking for and it helped you.
July 4: The Philippines gains independence from the United States, and begins fighting communist Huk rebels (Hukbalahap Rebellion). I hope I could help! :)