The Governor of a state or the Present of the U.S. has the power to declare martial law in case of a state emergency. Either case is debatable in the U.S. Constitution and the state's Constitution.
Maryland - to seize its railroad and protect the Northern capital (Washington D.C)
yes
Yes
Lincoln arrested state leaders who wanted to secede.
Maryland
He jailed some Southern sympathisers in Maryland, which was a slave-state in danger of voting Confederate. There was no trial, so this may have been under martial law, or maybe no law.
Abraham Lincoln
Its not something that's "used". It just happens. When there's chaos or the government falls apart. During Hurricane Katrina there was a state of martial law.Added: The above statement is only partly true, It does not "just happen." The Governor of a state or the President of the US can declare Martial Law.Added:Martial law was never declared during or after Katrina and the term does not exist under Louisiana state law. Furthermore martial law, or the suspension of habeas corpus, cannot be declared federally without the approval of congress and even then only in cases of rebellion or invasion. Individual states and the federal government can declare a state of emergency which is similar, but does not throw the Constitution out of the window.The last time the federal government applied martial law was in Hawaii during WW2 after the Pearl Harbor attack.Habeas Corpus, is "to see the body" it is a legal term meaning the judge wants the person before him, and martial law was declared in Katrina it does not take congress, that's the suspension of posse comitatus, the state governor can declare martial law and he did, in Katrina
because of the price hike of the gasoline in Libya
The Governor of a state or the President of the US. The latter is debatable as the Constitution makes no provision for martial law, only the suspension of the Writ of Habeas Corpus. That right is seemingly left to Congress in Article 1 Section 9 of the Constitution regarding the legislature and the limits on Congress. As for the governor of States being able to declare martial law, the right would be left to the individual state constitutions as all rights not prohibited to the States are allowed them per the Tenth Amendment. Again, it must be emphasized that the issue is debatable.
Maryland - to seize its railroad and protect the Northern capital (Washington D.C)