I wander thro’…
charter’d street, near where the charter’d Thames does flow.
Marks of weakness…
marks of woe = repetition to emphasise the despair.
Mind…
forg’d manacles = metaphor to show everyone is a slave to their life in London.
The hapless…
soldier’s sigh runs in blood down Palace walls.
The youthful Harlot’s curse…
blasts the newborn infant’s tear.
Blights with plagues…
the marriage hearse.
Black’ning…
Church = referencing pollution