from+When+Lilacs+Last+in+the+Door-yard+Bloom'd

1. "When Lilacs Last in the Door-yard Bloom'd" is a moving elegy written shortly after the assassination of Abraham Lincoln. What is the tone of the speaker?
 * WHEN lilacs last in the door-yard bloom’d, || ||
 * And the great star early droop’d in the western sky in the night, || ||
 * I mourn’d—and yet shall mourn with ever-returning spring. || ||
 * O ever-returning spring! trinity sure to me you bring; || ||
 * Lilac blooming perennial, and drooping star in the west, || ||
 * And thought of him I love. ||
 * And thought of him I love. ||

2. How is imagery used to reinforce the tone of the speaker?

3. Why will Whitman "mourn with ever-returning spring"?