Both Edwin Markham's poem "The Man with the Hoe" and Shakespeare's Sonnet 29 speak of mankind's agony when he is in a state of suffering and strife. Yet, one difference is that Markham's poem speaks more fluently on the state of being enslaved to labor, possibly even literally of the state of slavery, whereas Shakespeare's poem only speaks of having an impoverished fate. It also ends on a happier note.
Though he grew up in a free state, Charles Edwin Anson Markham was born in 1852 and grew up during the days of the Civil War and the failed Reconstruction in the South (1861 - 1865), both of which most likely significantly influenced him and his interpretation of the famous painting titled L'homme à la houe, by French artist Jean-François Millet, from which he derived inspiration for his poem "The Man with a Hoe," written in 1863. In this poem, he describes a man permanently bent from "centuries" of labor and staring at the ground. He describes the man as no longer having enough humanity in him to either despair his situation or to feel joy, as we see when the speaker asks, "Who made him dead to rapture and despair ...?" The possibility that the man with the hoe can be interpreted as being a slave is seen in the use of the word slave in the phrase "Slave of the wheel of labor" and in the reference to "masters, lords and rulers." He even goes so far as to question how a master will ever make human again a shape so distorted and restore to it its image of God, supposed to be present in all men, which can be interpreted as references to Reconstruction in the South, attempts to matriculate freed slaves into society as whole and free men, attempts that failed significantly due to persistent Southern corruption. Hence, all in all, Markham's poem looks at humanity suffering under severe and strenuous labor and questions the ability for such people to still maintain their humanity while also showing that restoring such humanity is both nearly impossible and absolutely essential.
Similarly, Shakespeare's Sonnet 29 describes the speaker as being in an "outcast state," like a slave, and being "in disgrace with fortune," which can be interpreted to mean impoverished, similar to a slave or to any human who suffers from poverty. Hence, one difference between Markham's and Shakespeare's poems is that Markham's poem speaks of slavery more directly, whereas Shakespeare's poem only references any troubled, impoverished soul who feels like an outcast from society. A second difference is that Shakespeare's speaker has the fortune of feeling uplifted from his wretched state whenever he thinks of the person he loves, as seen in the last six lines, making it a happier poem overall.