[Answer] This Wyoming ghost town got its start in 1867 and has more than 25 historic structures preserved.

Step 1 : Introduction to the question " This Wyoming ghost town got its start in 1867 and has more than 25 historic structures preserved. "

...1. South Pass City 2. Kirwin Mine 3. Old Trail Town 4. Spooky City

[Answer] The original Declaration of Independence is preserved in a bulletproof case filled with which gas?

Step 1 : Introduction to the question "The original Declaration of Independence is preserved in a bulletproof case filled with which gas?"

...The original Declaration of Independence still survives and is one of the most treasured papers in American history. It is stored in a titanium case filled with inert argon gas. The thick bulletproof glass sheet over it is tinted very heavily to prevent damage from sunlight or UV rays. Similar preservation techniques are used to protect the Bill of Rights and Constitution. The Declaration of Independence remains on display in the rotunda of the National Archives, where it is seen by roughly 6,000 tourists every day. At night, when the crowds have all gone home, the case is lowered 22 feet into a vault.