What is the meaning of "inlooped flags" in a poem of Whitman (When Lilacs Last in the Dooryard Bloom'd)? He is describing the Lincoln funeral:

Coffin that passes through lanes and streets,
Through day and night with the great cloud darkening the land,
With the pomp of the inloop'd flags with the cities draped in black,
With the show of the States themselves as of crape-veil'd women standing,

Does he mean flags are looped over the coffin and covered it?