What is the main historical event lowell refers to in his poem “for the union dead”?

He refers to civil war.

In this poem, Lowell thinks of the controversial Civil Rights Movement and the images of the integration of black and white schoolchildren Lowell had recently seen on television.

in the sonnet 116 written by william shakespeare we can analyze the symbolism and say that he reuses the idea of love like a guiding star for the sailor.

reading through the poem we find out that in the line 7 there is a metaphor for the lover that is heading through the life events by love itself .