Both Abraham Lincoln and Frederick Douglass wanted to abolish slavery. They both were fighting a common fight which had divided the nation.
Douglass always looked up to Lincoln and his ways. They both even spoke about abolishing slavery from the nation completely. So, after Lincoln's death, Douglass had lost a friend. Still he carried out Lincoln's work speaking against social injustice and racial discrimination. He demanded equal rights for African Americans.
Thus, Lincoln's death was also a calamity for the nation as African-Americans had lost a leader who led them fighting for their rights and justice.
Answer: using slang or otherwise informal language isn't trustworthy. It shows that the writer is taking the subject seriously and putting effort into their work.
