Indignant
Indignant: Exhibiting or characterized by anger aroused by something unjust, mean, or unworthy
syn. annoyed, irate, disgruntled, livid

From Frederick Douglass’s "An Appeal To Congress For Impartial Suffrage":

Statesmen of America! beware what you do. The ploughshare of rebellion has gone through the land beam-deep. The soil is in readiness, and the seed-time has come. Nations, not less than individuals, reap as they sow. The dreadful calamities of the past few years came not by accident, nor unbidden, from the ground. You shudder to-day at the harvest of blood sown in the spring-time of the Republic by your patriot fathers. The principle of slavery, which they tolerated under the erroneous impression that it would soon die out, became at last the dominant principle and power at the South. It early mastered the Constitution, became superior to the Union, and enthroned itself above the law.

Freedom of speech and of the press it slowly but successfully banished from the South, dictated its own code of honor and manners to the nation, brandished the bludgeon and the bowie-knife over Congressional debate, sapped the foundations of loyalty, dried up the springs of patriotism, blotted out the testimonies of the fathers against oppression, padlocked the pulpit, expelled liberty from its literature, invented nonsensical theories about master-races and slave-races of men, and in due season produced a Rebellion fierce, foul, and bloody.

This evil principle again seeks admission into our body politic. It comes now in shape of a denial of political rights to four million loyal colored people. The South does not now ask for slavery. It only asks for a large degraded caste, which shall have no political rights. This ends the case. Statesmen, beware what you do. The destiny of unborn and unnumbered generations is in your hands. Will you repeat the mistake of your fathers, who sinned ignorantly? or will you profit by the blood-bought wisdom all round you, and forever expel every vestige of the old abomination from our national borders? As you members of the Thirty-ninth Congress decide, will the country be peaceful, united, and happy, or troubled, divided, and miserable.

        
In this passage, Frederick Douglass portrays himself as an indignant former slave who has lived a difficult life both as a slave and as a free man. Douglass repeatedly warns for statesman to “beware what you do,” as he urges that they cannot fall victim to the same injustices that have hindered their struggle for freedom for years. In his excessive cynicism, Douglass urges that the prejudices be brought to and understanding and immediately ceased.  His harsh word choice emphasizes the suffering his people have endured and creates a sense or urgency for the rendering of this devastation.

Douglass, Frederick. An Appeal To Congress For Impartial Suffrage The Literature      Network, 2000, 15 November 2004.
     < http://www.online-literature.com/frederick_douglass/990/ >