Originally Posted by SmokinDVM
"Those who profess to favor freedom, yet deprecate agitation, are men who want crops without plowing up the ground. They want rain without thunder and lightening. They want the ocean without the awful roar of its many waters. This struggle may be a moral one; or it may be a physical one; or it may be both moral and physical; but it must be a struggle. Power concedes nothing without a demand. It never did and it never will."
– Frederick Douglass, African-American abolitionist
As demonstrated above, the US has a history of protestors. They were less effective in the 19th Century, compared to the 20th, most probably due to transportation difficulties making it next to impossible to get large groups together. I don't think it was due to any respect for the office, unless the person holding it was really deserving.
It's my understanding that Lincoln used to have people gather in certain areas of the White House, and would actually go and talk to them. Even during the Civil War, he would still carry out that practice, often speaking with the families of soldiers who had fallen in battle.
The present admins SOP is to avoid the subject of dead soldiers altogether, especially involving the families.