Answer:
The effect of writing the poem after the event has already happened is that it helped glorify those six hundred armymen who volunteered to walk towards their death. It also brings a patriotic emotion.
Step-by-step explanation:
"The Charge of the Light Brigade" is a poem written by Alfred Lord Tennyson.
The poem was written on the event that took place on October 25, 1854, and Tennyson wrote the poem on 2nd November 1854, published on 9th November 1854.
The effect of writing the poem after the event had happened created an effect of patriotism and a tribute to those six hundred armymen.