It is not true that before Fort Sumter the majority of northerners favored letting the South go peacefully. There *was* some "good riddance--let them go" talk among some extreme anti-slavery men--but it is unclear how sincere it was. There is a good discussion of this in Stampp, *And the War Came*: "Charles Sumner advocated disunion--but only in private and largely as a kind of intellectual excursion into political theory. In practice he encouraged the movement to prepare the Massachusetts militia to defend Washington and enforce the laws. On November 27 Henry Ward Beecher boldly proclaimed that he cared little whether the South seceded. Two days later he preached a Thanksgiving Day sermon which raised the banners for a war against the Slave Power...For a proponent of peaceful disunion Garrison's Boston *Liberator* became surprisingly agitated about southern 'treason.' It charged that secessionists were determined to provoke a civil war and castigated the Democrats who allegedly opposed the punishment of 'traitors.'" Stampp also shows how Horace Greeley's alleged support of peaceful disunion was so qualified as to be meaningless. Most talk of voluntary disunion among anti-slavery men was really just meant to oppose the idea of saving the Union through yet another cowardly compromise with the Slave Power.
You may be misled by all the Northerners who said they did not advocate "coercion" of the South. Most of these people however supported "enforcment of the laws." To quote an old soc.history.what-if post of mine (sorry for any links that may no longer work):
***
In fairness, Buchanan in the same speech where he said that the federal
government could not force states to remain in the Union (even though he
not only averred that secession was illegal but IMO gave the best single
argument ever made against its legality [1]) did say that the federal
government had the duty to enforce the laws. This puzzling distinction
between "coercion of states" and "enforcement of the laws" was widespread
at the time--Republicans as well as Democrats used it. "Coercion" meant
marching an army into the South to compel the states to rescind their
ordinances of secession, return their Representatives and Senators to
Congress, haul down their flags, etc.; "enforcement of the laws" meant the
US government holding its own forts and other property and collecting the
tariffs. Furthermore, it was held that enforcement of the laws did not
mean using force against states, because federal laws acted upon
individuals (however numerous, and even if they included the governor, the
state legislators, etc.) not states.
For an example of a Republican using the same distinction, see Senator
Lyman Trumbull:
"This phrase, 'coerce a state,' is a phrase calculated to mislead the
public mind...Nobody proposes to declare war against a State. That would
admit at once that the State was out of the Union--a foreign Government.
Of course, we cannot declare war against a State. Nobody proposes to
coerce a State or to convict a State of treason. You cannot arraign a
State for trial; you cannot convict it or punish it; but you can punish
individuals...The Government has the power to coerce and to punish
individuals who violate its laws."
http://www.constitution.org/cmt/mclaughlin/chus.htm
So Buchanan here is at worst guilty of a sophistry--if that is what it
was--[2] shared by Northern Democrats and Republicans alike (and by some
Southerners; Senator Andrew Johnson of Tennessee made remarks to the same
effect). Of course, the Republicans didn't see it that way because they
viewed his words in the context of four years of a blatantly pro-Southern
administration--and also in the context of the rest of the speech, where
Buchanan put the whole blame for the development of sectional conflict on
the North for its agitation of the slavery question.
(Though I think Buchanan was clear enough, I must acknowledge that some
distinguished scholars disagree. Andrew McLaughlin in his *Constitutional
History of the United States* writes "If, as has been asserted, President
Buchanan made a distinction between coercing states and enforcing the
execution of the laws on persons, he succeeded in clothing his utterances
with obscurity."
http://www.constitution.org/cmt/mclaughlin/chus.htm)
[1] "In that mighty struggle between the first intellects of this or any
other country, it never occurred to any individual, either among its
opponents or advocates, to assert or even to intimate that their efforts
were all vain labor, because the moment that any state felt herself
aggrieved she might secede from the Union. What a crushing argument would
this have proved against those who dreaded that the rights of the states
would be endangered by the Constitution!"
http://www.britannica.com/presidents/article-9398250 Indeed, if it had
been assumed at the time of the ratification of the Constitution that
there was a right to secede at will, the vehemence of the opposition to
the new document by the Antifederalists is utterly inexplicable.
[2] The distinction certainly looks like maddening hairsplitting to us
today, and seemed that way to most Southerners at the time. As Kenneth
Stampp wrote in *And the War Came,* it was not much comfort for
secessionists that the Yankee bayonet was a symbol, not of Coercion, but
of Law. Yet the distinction between the federal government acting on
states as such or on individuals did have firm roots in the intentions of
the Framers of the Constitution:
"Soon after the Convention adjourned Madison wrote to Jefferson: 'It was
generally agreed that the objects of the Union could not be secured by any
system founded on the principle of a confederation of Sovereign States. A
voluntary observance of the federal law by all the members could never be
hoped for. A compulsive one could evidently never be reduced to practice,
and if it could, involved equal calamities to the innocent & the guilty,
the necessity of a military force both obnoxious & dangerous, and in
general a scene resembling much more a civil war than the administration
of a regular Government. Hence was embraced the alternative of a
Government which instead of operating, on the States, should operate
without their intervention on the individuals composing them; and hence
the change in the principle and proportion of representation.' October 24,
1787. Madison, Writings (Gaillard Hunt, ed.), V, p. 19. Ellsworth,
addressing the Connecticut convention, said: 'Hence we see how necessary
for the Union is a coercive principle. No man pretends the contrary: we
all see and feel this necessity. The only question is, Shall it be a
coercion of law, or a coercion of arms? [Hamilton had used the same
expression in the Convention at Philadelphia, June 18] ... I am for
coercion by law--that coercion which acts only upon delinquent
individuals." Elliot, Debates, II, p. 197."
http://www.constitution.org/cmt/mclaughlin/chus.htm
. Cobb’s will warn the people if war comes this very well will disturb all commerce . Lincoln I could imagine before war has come Lincoln would eventually blockade the Deep South in there mission to collect tariffs at sea. The river is domestic trade and to close it or charge tariffs would Be to recognize they are separate if not independent. Douglas also favored surrendering the forts except in for 1 fort in Florida for coaling purposes only. Remember in history all that trade down the Mississippi went away,but that wasn’t what the wanted because that was there income! Even without Fort Sumter Douglas would support his country the Union,but would agree Lincoln bullied them.
? Not only is that not a major flesh wound it didn’t stop him from doing his duty. He should get a doctor 
And patch him up . Remember Albert Sidney Johnston if he just had a doctor to give them a tourniquet I recall he would have been fine instead of bleeding 
to death.
. Actually it looks like that they could actually cross during the day .
The Union would be Abel to march to Richmond without big enough opposition to stop them. The csa isn’t invading the north they are taking back the USA 
capital that is southern . Cobb’s (any competent leader ) would likely warn those forces not to destroy the buildings because we plan to use them. The south’s objective is remember cutting of supplies to force the union to evacuate. Yeah if the union is retreating then the Confederates can advance Beyond the bridges.
.
. The propaganda would be have more believer (if the south took DC ) any southern could beat at least 10 Yankees . But that propaganda was stupid,ignorant and arrogant .
