The film starts with Robert Smalls as a child slave. Smalls is a house slave who is favored by his master and is treated kindly as a pet with Robert adoring his master. His mother, horrified by Robert growing to become fond of slavery, requests to their master that Robert works in the fields picking cotton to experience the harsh life of the field slaves. Their master agrees, and while Robert at first resents his mother, his forming camaraderie with the field slaves and witnessing the brutal horrors that the overseers inflict upon them open his eyes to the evils of slavery and lit a fire inside of Robert to escape and experience freedom.
The movie flashes forward to Robert as a young man, marrying his wife Hannah, starting a family and working in the Charleston harbor. Robert develops a love for the sea and sailor's life, often being conscripted to serve as a helsman for Southern vessels where Robert learns many skills of running a ship. Robert hopes to earn enough money one day to free him and his family, but with the abysmal wages he is paid it is an impossible dream. Everything changes when the Civil War breaks out, and due to the needs of the war effort and the South's poor tradition and experience in naval affairs, they conscript slaves to fulfill menial labor and grunt work in the Confederate Navy with Robert being placed as the helsman of a Confederate transport ship, the CSS Planter.
Robert fulfills his work very well and gains the confidence and favor of the Planet's white crew while he bonds with the other enslaved crew of the Planter. Getting to finally fulfill his dream of sailing, Robert is at first happy, but seeing the abuse the Confederate military places on slaves and Confederate soldiers boasting about how they'll lynch Lincoln to protect their rights to own Blacks reminds him of his childhood subservience and makes Robert start to be horrified and resent his work. Seeing that his hands are used to pilot a ship that can go anywhere in the world, Robert sees that he can finally achieve his freedom and he begins to form a conspiracy with his fellow slaves to escape.
On May 19th, 1862; the Planter stops for shore leave after having successfully dismantled an abandoned fort. The officers depart and Robert asks the Captain if the slave's families could visit, which he accepts due to liking Robert. Robert's family and those of the other slaves reunite with their loved ones where Robert reveals the plan for all of the families to sneak aboard the Planter where together they shall escape Confederate waters and head to the Union. Many of the wives are frightened by the plan, fearing what will happen to their children if they get caught. This makes the slaved crew uneasy until Hannah Smalls makes a defiant speech about how it is a risk they must take for the future of their children, so they may spend the rest of their lives free and their grandkids will never know the bondage of slavery. Hannah's bravery inspires everyone to go aboard with the plan.
On the morning of the 13th, Robert and the slaves execute the plan as the white crew and officers are partying and drinking in Port Royal. Picking up their families who were hidden in a vacant steamship, they would make their way across the South Carolina coast past numerous Confederate forts and patrolling ships. Robert wearing Captain Relyea's straw hat and a spare uniform, is able to fool the passing Confederate sailors in the dimly lit early morning by pretending to be Captain Relyea, adopting his known mannerisms and giving the correct hand signals which Robert had observed numerous times before. Each time they pass a patrol there is heavy tension and anxiety with many believing they would be caught. Hannah rallies the men and women to tend to the ship while Robert confidently steers the boat, being compeltely calm and collected in spite of the ongoing terror of the situation. After a tense close call with Fort Sumter, Robert pilots the Planter to the Union blockade, surrendering the ship with Union sailors being astonished that a group of slaves successfully stole the vessel.
Meeting with Union officers, Robert proves to be a boon to the Union war effort as he provides critical intellegence on the state of South Carolina's coastal defenses and shares a code book of Confederate Naval signals and passages. The information allows the Union to capture many Southern islands and strengthen its blockade. Across America, the legend of Robert Smalls grows with Smalls being heralded as an American hero in the North with abolitionists such as Frederick Douglas using Smalls as an example of the intellegence and capabilities of the Black Man. Across the South, Robert Smalls is talked about as if he were a boogeyman to the white planters while slaves gather in hushed circles and share Robert's tale as a story of hope and inspiration that soon they shall be free.
The second act covers Robert's service to the Union throughout the rest of the war. As a war hero, he makes a number of fundraising trips throughout the North, sharing his experiences with slavery to encourage Americans to fight on and end the vile existence of the Confederacy. In one scene, Robert would travel to Washington D.C and personally meet with Abraham Lincoln to discuss the topic of enlisting former slaves into the Union Army. Lincoln is at first reluctant, fearing that it would create backlash against the war effort and unsure if the slaves would be great soldiers, to which Robert passionately defends the fighting spirit of the slaves and promises that if one is put into uniform then they will fight and die for the stars and stripes more than any white man. The scene ends with Lincoln moved and thanking Robert for his insight, with it suggested that Robert gave Lincoln partial inspiration for the Emancipation Proclomation.
In March of 1863, Robert enlists to fight in the War and is placed as the pilot of the USS Crusader, beginning Robert's illustrious two year career with the US Navy. While Robert at first is treated with skepticism by the Union crews as a propaganda piece; Robert's strong character, skill and dependability win over his superiors and the naval enlisted, with Robert being accepted into their ranks and treated as an equal by white men for the first time in his life. The second act shows the many battles that Robert partook in the war with Robert performing with high valor and bravery throughout the fights, steering his ship with excellent mastery. Robert also proves to be a valuable strategic asset by helping Union ships to locate Confederate mines and disarm them. Robert shifts service between many ships of the war, but for the majority he is assigned to the Planter, rechristened as a Union naval ship. The high point of Robert's Civil War service is on December 1st of 1863 where Robert while piloting the Planter comes under heavy fire at Secessionville. Robert's contemporary superior, Captain James Nickerson, flees in cowardice to hide in the coal room. Without a Captain, Robert takes command of the Planter and valiantly leads them to safely to Union waters without any casualties. For this act, Robert is promoted to the rank of brevet Captain by Quincy Adams Gilmore and is recognized for his heroism.
Other highlights of the Second Act is Robert traveling to Philadelphia as an unofficial delegate of South Carolina at the Republican National Convention. There, Robert experiences his first taste of politics and develops a passion and rhetorical strength in it, rubbing shoulders with many prominent Republican politicians. In a true incident mirroring Rosa Parks nearly a century later, Robert takes a streetcar and is told by its bigoted driver to give his seat to a white man and sit in the overflow section. Outraged, Robert refuses to ride the Streetcar and walks, with the incident acting as a casus belli which leads to Pennsylvania integrating public transporation. In December of 1864, Robert joins General William T. Sherman in his March through the South and at the end of the war is employed by the Freedman's Bureau as the Planet's Captain to provide critical supplies to freedman refugees.
The Third Act of the film covers the post-war years of Robert Smalls' life with scenes transitioning between major points from Juneteenth to his final term as Representative of the United States. In Reconstruction, while Robert is able to achieve immense wealth and help develop his local community, he fights a brutal and losing battle to save South Carolina and America from the rise of the Redeemers who wish to turn back the clock and keep Black Americans as living just as, if not worse than their slavery days. While Robert manages to achieve victories such as promoting free education for all South Carolina children and passing Civil Rights, with the end of Reconstruction despite his impassioned pleas with President Hayes and the Republican Party, the Dixiecrat Order is imposed and thus Black Americans while free, do not experience true liberty. The final scene shows Robert on his deathbed, surrounded by his family and loved ones, praying that some day America may know true Freedom, and then showing a montage of famous Civil Rights leaders who followed Robert's footsteps, showing that such a "Small Man" had a Giant footprint and legacy.
