John Geary's pocket diary begins with a few pages of miscellany, including a list of grocery purchases and notes on physics. Diary entries begin on December 31, 1846, with details of Geary's day in Pennsylvania with the American Highlanders, who had set out to fight in the Mexican War. Entries were made nearly every day, although less frequently towards the end of the diary, and vary in length from a few lines to a few pages, some of it written in very tiny script.

Geary embarked from New Orleans January 23, 1847, and arrived in Vera Cruz, Mexico, in April via the "delectable" island of Lobos. He included lengthy descriptions of the exotic plant and animal species he encountered, comparing them to those he knew in Pennsylvania, as well as descriptions of Mexican towns and battlefields, like the one at Sierra Gorda where the stench of rotting carcasses "was very annoying and in many instances almost suffocating." His entries are peppered with Spanish phrases and interesting anecdotes, such as the incident on May 19, 1847, when four U.S. soldiers were punished for stealing in the town of Jalapa. The soldiers were whipped in public with the "cat," their heads shaven, and then driven through the town with "ROBBER" painted on their backs. Geary noted that while they might have deserved it, the manner in which they were punished was a "relic of barbarism, and ought not to be continued in an enlightened age."

In another interesting entry from June 9, Geary went to a cemetery for the funeral of a fellow soldier. Next to the grave were thirty skulls piled on top of each other that were unearthed during the digging process, the former contents of a mass grave. As he "carelessly tossed about these late abodes of the human mind," he wrote that "strange reflections" on life and death passed through his mind, some of which are included in the entry. In this same entry he reflected on the war relief situation: "In this war we have lost very many brave men, many now languish in sickness, and are almost destitute of proper medical attendance, of nourishing diet, of kind nurses. No one to speak kind words to alleviate their sufferings." He went on to criticize philanthropists who concerned themselves with foreign people and foreign causes, among them Christian missionaries in China and relief societies for Irish peasantry. "Charity," he asserted, "begins at home." On September 10 Geary witnessed the execution of sixteen American soldiers, "all Irishmen," who deserted and joined Mexican forces. Thirteen others were whipped and branded with the letter "D" (for deserter) on their right cheek. Summarizing his sentiments upon witnessing this event, Geary wrote: "Their execution made no impression upon my mind whatsoever, nor the least pity excited my breast."

With a few exceptions, such as the battle of La Hoya, Geary was brief when detailing battles in which he was engaged. For instance, less than a month after the surrender of Mexico City on September 14, which is recounted in a half-page entry, he experienced an earthquake on October 2, which he used nearly two pages to describe. Most entries, however, relate news from other camps and provide a clear picture of the progress of the war. The diary ends with a blank entry on February 11, 1848, while Geary was still in Mexico.

John Geary's letters to his second wife, Mary Church Henderson, begin April 12, 1859. His pre-Civil War letters include messages from Harrisburg that mention bills he defended, from Springdale that detail farm news and his boys' schooling, and from New York that speak of legal issues including the Girard estate case, in which he represented the tycoon's heirs who sought to overturn Girard's will. Girard's heirs lost their case to the city of Philadelphia and the will was sustained. Beginning in December 1860 Geary's letters to Mary express his fears for the future of the country. In January 1861 he wrote: "I fear the day of reconciliation has passed and that our beloved country is forever severed into fractions that will never again be united."

Geary joined the Union forces in 1861 as colonel of a regiment of volunteers he helped to raise, the 28th Pennsylvania Infantry. His Civil War letters to Mary were written several times a week and vary in length. They include Geary's impressions of the places the army passed through, updates on his physical and mental health, pledges of love to his wife and children, and his reflections on the war. Geary's letters also contain first-hand news reports from the front and his accounts of several major battles, including Gettysburg, Wauhatchie, Atlanta, and Savannah. In a letter from July 5, 1863, after leaving Gettysburg, he wrote: "I have seen so much death and suffering this month that I am perfectly sick of the times. My very clothes smell of death. The stench of the battle fields was horrible and beyond description." On November 2, 1863, his and Mary's wedding anniversary, Geary's mind was elsewhere after the battle at Wauhatchie, which was won by the Union but not without the painful personal loss of his son, Edward: "Were it not for the almost impenetrable gloom which hangs around me since the death of my beloved son, I would enjoy it. Poor dear boy, he is gone, cut down in the bud of his usefulness."

Geary was made commandant of the city of Savannah after securing its capture in December 1864. In a letter from December 23, he proudly announced the news to his wife: "My eventful career is still upon its everlasting whirl. I am now the Commandante of the city in honor its capture by me and of the surrender to me." His letters include the details of his command in Savannah, the Carolinas campaign, and his march homeward once the war was over.

This series also includes a volume of typed transcripts of Geary's letters.

The twenty-three scrapbooks of newspaper clippings from around the country contain articles that span the course of Geary's political and military careers. There are articles with news from Mexico, from San Francisco and other west coast towns, from Kansas, and from Pennsylvania. Several poems and song lyrics also appear sporadically throughout the scrapbooks. In the first pages of the 1852-1857 scrapbook, pages have been pasted from an irreverent book with many drawings entitled "The Adventures of the Firm of Brown & Jingo in California." Printed on the front cover is the following announcement: "Compiled entirely and with the strictest adherence to truth from Mr. Brown's own private Journal -- without that gentleman's permission either (and here Mr. Brown is recommended in the future not to leave his Journal in charge of the bar keeper wherever he goes!!!!)." Several of the scrapbooks contain many articles with Civil War-related news. The majority of the scrapbooks, however, are post-Civil War and document Geary's terms as governor of Pennsylvania. His advocacy of constitutional, electoral, and educational reforms are well represented in the scrapbooks' articles, as are several railroad and coal mining-related issues, including the Scranton mine riot in 1871 during which Geary called in the state militia to quell striking workers. There are several pages of clippings that announced his death in 1873 and provide biographical information.

The volume entitled "In Memoriam" was prepared posthumously by the surviving members of Geary's staff during his service as major-general during the Civil War. His staff members professed in that they sought to avoid eulogy and sentimentality and wanted to simply state the facts of his service:

This subseries also contains a three-page dictation of an incident related to an unknown person by Mrs. John McMillan in London in 1913. Mrs. McMillan dressed Geary's wounded arm in her friend's home after the Battle of Cedar Mountain in 1862 and in the account she told how she mistook a nerve in Geary's wounded arm for a thread and attempted to pull it out, which prompted a great exclamation.

Edward Geary's letters to his stepmother, Mary Church Henderson, begin on his sixteenth birthday, September 1, 1861, while he was still in Philadelphia preparing for his enlistment in the Union army. Edward's approximately 150 letters include accounts of battles in which he was engaged, including Sandy Hook in July 1863, his impressions of new places, personal reflections, and inquiries as to the well-being of his siblings.

He wrote home approximately once a week and claimed he would have done so more often if he could, but was prohibited from doing so by his soldierly duties. Even so, his thoughts were still of home and in one letter to Mary he asked: "Have your ears burned any to-day mother? If thinking about a loved one would make their ears burn yours must have pained you very much." His letters to Mary reveal a deep tenderness for her. Even before he left Philadelphia to enlist, he wrote to her of his inability to get over his "home sickness or rather mother sickness" and professed to her that "if you were my own mother I could not love you better than I do." He often inquired after his little sister, "Pet," whom he looked forward to playing with once home, and his other family members. Edward also often mentioned his father and his younger brother Willie, who served as a drummer boy until 1862, in his letters to Mary and wrote to her of his knowledge of their whereabouts and occasionally of his meetings and consultations with his father, as in a letter from September 4, 1863, in which Edward wrote that Geary advised him to turn down an appointment to the captaincy of Hampton's Pennsylvania Battery, since the affairs of the unit were "very unsettled."

In several letters Edward expressed his desire to complete his college education once he returned home, although as the war dragged on his letters point to a sense of hopelessness and alienation. On August 29, 1863, one week before his eighteenth birthday, he remarked: "How differently situated I am from what I expected to be at this time! I expected to be able to attach A.B. to my name, and to be commencing the study of some profession instead of which I am forgetting all I did know, and am so situated as to be unable to improve idle hours. I was just going to wish that I could spend my birthday at home, but I have had so much experience in the fallacy of wishes, lately, that I think it would be time saved to discontinue the practice." In a letter from September of 1863, Edward wrote to his stepmother from Alexandria, Virginia: "Civilization has a very strange affect on me, after having become barbarized in the wilds of Virginia. Everyone I see appears so foppish and conceited, merely because they are well dressed and mannerly, I suppose, that I become disgusted immediately. I am becoming more and more careless every day, and am much afraid if we do much more campaigning, I shall forget what little knowledge I did possess in regard to etiquette, etc."

The last letter in this subseries was written on October 13th, 1863, from Murfreesboro, Tennessee, with his comments on that town and its unsavory citizenry and ends with a wry announcement of the evening's menu: "What have we! Mush and milk. Hurrah! My favorite dish." Edward Geary died later that month in the battle of Wauhatchie in Tennessee, as lieutenant of his battery.

Miscellaneous items include a reproduction of a photograph of Edward Geary. Noted on the photograph is "[ca. June 1862?]." Also included is a letter from M.L. Goodman, who is of unknown relation to Mary Church Henderson, dated November 15, 1863, which offered consolation upon the death of her stepson Edward.

This series also includes one folder of typed transcripts of Edward's letters.

Seven letters addressed to Mary Church Henderson, dated from February 28, 1862, to March 18, 1864, from her brother-in-law, Rev. Edward R. Geary, discussed news of the war and offered her consolation upon the loss of her step-son Edward. His letters also provide a brief record of his travels during this time to Mexico, Oregon, and New York. Typed transcripts of Rev. Geary's letters are present in this subseries.