The diary covers the dates December 31, 1862 through March, 1863. Entries primarily detail Larimer's travels sailing from Norfolk to Moorhead Station, then by train to New Bern, N.C, on by ship to Beaufort, S.C. and then on to St. Helena Island 2 miles north of Hilton Head, where he disembarked and stayed throughout February. He remains on St Helena throughout March and in April, is back on ship to where the 62nd Regiment camps on Folly Island; mentions some activity around Fort Sumter, with the Rebels located on Morris Island; some fire as the Rebels try to resurrect the sunken ironclad [Keokuk] April 16, 1863.

In May, 1863, Larimer describes the building of defenses and fatigue duty. June, 1863, sees some sea action, including spotting a Rebel ship that has gone aground; some shelling by the Rebels. July 10-11, 1863, describes action of Union gunboats keeping up steady fire on Morris Island in Charleston Harbor; some infantry storm the fort July 18 with heavy losses. July 19, Union wounded returned by boats to Hilton Head and Beaufort following the attack; describes losses of storming party as 1,500 killed, wounded or missing; reports that in 62nd Regiment, 155 were killed wounded or missing, and in his Co. C, 19 killed, wounded or missing; shelling continues and ironclads engage in activities.

In August 1863, he tells of constant shelling, much sickness in camp. August 22, steady fire all day on Fort Sumter with a boat bringing a flag of truce at night; August 23, 1863, the whole ironclad fleet operating at daybreak--a slackening of fire in the evening; August 27, 1863, steady fire all day, his regiment in front in entrenchments.

September 2, 1863, ironclads bombard Forts Gregg and Wagner with Rebel works heavily damaged and guns silenced; September 7-enemy forces evacuate Forts Gregg and Wagner on Charleston's Morris Island. U.S. forces occupy Forts Wagner and Gregg. September 8, the ironclad fleet attacks Sullivan Island batteries with success. September 20, Federal forces shell Fort Johnson and Castle Pinckney

In October 1863, Larimer receives news of fighting at Chattanooga; every day, slow fire of Rebels on Union works at Cummings Point; October 29, regiment marches to south end of Folly Island where it pitches tents. November, 1863, drills and usual routine. December 1, 1863, regiment moves to Hilton Head Island.

On January 1, 1865, Larimer is encamped in front of Richmond, with rebel camps in view. January 25, mentions that three Rebel ironclads attempt to pass the Federal fleet and go down river but are attacked; one sunk, two run ashore and abandoned. February 14, receives news of capture of Charleston, S.C. February 17, reports that two men from the 2nd Division were hung in front of the men for crimes of murder, robbery and desertion. March 1-11,1865, entries mention his learning of President Lincoln's inauguration, Sherman's burning of Columbia, S.C. and Jubal Early's defeat by General Phillip Sheridan in the Shenandoah Valley

March 12, reports being reviewed that day by Generals Ulysses S. Grant, Edward Otho Cresap Ord, John Gibbons and Robert S. Foster. March 25, troops ordered to get ready to move. March 26, participates in a review by President Lincoln and his family and General Grant. March 27, receive orders to move; marched all night, crossing the James and Appomattox. March 28, halted at 6:00 a.m. and resumed march at 11:00 a.m.; column consists of two Divisions, 25th and 26th corps; marched two and one-half miles north of [Hatchers Run ?] and bivouacked for the night. March 29, moved one mile north westward from the line on the left of the 6th corps, relieving the 2nd corps; detailed for picket duty; hears brisk musketry in the direction of Petersburg. March 30, relieved from picket duty at 11:00 a.m.; tells of skirmishing. March 31, in line at breastworks all day

April 1, quiet on the picket lines; reports battle opens on Petersburg line at 11:00 p.m. and continues all night. April 2, Rebels open fire at 2:00 a.m., but are driven back at daybreak and hemmed in by Sheridan; 2,200 captured. April 3-15, describes in some detail the troop movements of his division and engagement in the final battles at Petersburg and Appomattox; tells of poor weather conditions; of the march toward Richmond with a halt near Farmville and an engagement there with the enemy; mentions bivouacking at Appomattox Court House, the attempts to find rations for the captured Rebel troops and difficulties of managing captured army; notes surrender of General Robert E. Lee at 4:00 p.m. April 9; mentions Abraham Lincoln's assassination. April 16, writes of departure of his unit from Appomattox Station on march to Richmond.

May, 1865, short entries include some brief descriptions of activities while encamped outside of Richmond--inspections, drills and weather. June, some routine camp activities with a mention June 9 of a beating and robbery outside the camp of Capt. H. K. Hitchcock. July, more routine camp activities with some talk of going home; visits to Richmond; his group leaves camp at the end of the month and goes by boat to City Point

Entries in August and September 1865, mostly tell of movements of individuals, such as transfers, leaves, detachments from service and making mustering out rolls. The last entry is for December 3, 1865, while Larimer is working on mustering out rolls