This letter was written by Mary Boynton (Wister) Ruschenberger (1807-1893), the daughter of Charles Jones Wister (1782-1865) and Rebecca Bullock (1782-1812). Clearly Mary wrote the letter while pregnant and residing with her parents in Germantown, Pennsylvania.
Mary wrote the letter to her husband, Dr. William Samuel Waithman Ruschenberger (1807-1895) who was a surgeon in the United States Navy stationed at the Brooklyn Naval Yard Hospital. The following biography appears in Wikipedia:
After attending schools in Philadelphia and New York he entered the Navy as surgeon’s mate, 10 August 1826. He was graduated in medicine at the University of Pennsylvania in 1830, and was commissioned surgeon, 4 April 1831. He commissioned with the U. S. Sloop-of-war Peacock in 1836, and accompanied the second mission of diplomatist Edmund Roberts to Muscat and Siam, subsequently fleet surgeon of the East India Squadron 1835–1837. Ruschenberger was attached to the naval rendezvous at Philadelphia 1840–1842. At the Brooklyn Navy Yard hospital 1843–1847, he organized the laboratory for supplying the service with unadulterated drugs. He was again fleet surgeon of the East India Squadron 1847–1850, of the Pacific Squadron 1854–1857, and of the Mediterranean Squadron from August 1860 until July 1861. During the intervals between cruises he was on duty at Philadelphia. During the Civil War he was surgeon of the Boston Navy Yard. He was on special duty at Philadelphia 1865–1870, was the senior officer in the medical corps 1866–1869, and was retired on 4 September 1869. He was president of the Academy of Natural Sciences of Philadelphia 1870–1882, and president of the College of Physicians of Philadelphia 1879–1883. He was commissioned medical director on the retired list on 3 March 1871. Dr. Ruschenberger published some of the results of his investigations during his cruises, by which he had acquired a wide reputation.
He also served as a member of the Board of Appointments whose purpose was to form rules and plans for the United States Naval Academy. Dr. Ruschenberger rose to the rank of commodore before he retired.
Addressed to Dr. W. S. W. Ruschenberger, U.S. Navy, Navy Yard, New York
Monday Morning, March 18th 
I have just received my dear husband’s two letters. One ought to have come Saturday night, but did not, as we send to the [post] office every night, & when I think it probable that I shall get a letter in the morning too. There is no mail to or from here on Sunday. I do not think you could easily persuade me that my pen is equal to [Sir Walter] Scott or [James Fenimore] Cooper’s but I can believe you do not intend to flatter me when you say you would rather pay for a sheet from me, than for a volume from them. The book you speak of I had intended purchasing as I thought something might be gained from it. Is the Botony ready for publication? Papa asked the other day if you had done writing.
I am glad that [William P. C.] Barton ¹ is learning to be civil. I expect he feels a little afraid of losing his office. You do not say anything about the prospect of succeeding Barton upon which Dr. Belton is so certain. I told him you had no idea of stepping into his office.
When I waked this morning, I said to myself this day two weeks will be the 1st of April & I made up my mind you would not be here before the 2nd on account of the pay, but your letter induces me to expect you a day or two before that time, & I assure you I shall not be disappointed as it seems very long since I have seen you. I have not been able to walk since I have seen you. I have not been able to walk since Thursday on account of the weather which has been very wet, & it is now snowing a little. S. L. Wister drank tea here last night, & I went with her to church. Ann came from town in the afternoon, but I have not yet seen her.
I hardly know myself what to put in the hotbed beside salad, cabbage, as I understood from Briggs that they raise eggplants, tomatoes &c. in the Hospital Hotbeds. Cauliflower and broccoli will be put in. The latter is easier to raise than the former & very nearly as good. I would like some flower seeds to go in, nor portulacca, but any that are labeled if you can find out their names they ought to be marked. Papa will give me some superior sugar-corn. He says the shaken potatoes that Mr. B. spoke of are the best kind, if they can be got.
I have not been obliged to use an enema since I left home. I have taken the pills I brought with me twice. I should have abandoned ale, but the water is so bad, I can scarcely drink it. However, I will renounce the malt pen today. I can’t tell what the oil is you recommended to be mixed with rhubarb. I am not particularly anxious to use the lancet which is an operation I object to. Walking is so painful that it is a great task. I have not seen Will since I came to Germantown, but sent him word about the casks. Have you got to the end of the ale? I wish you would get yourself something good to eat. Have you plenty of eggs? I do not like you to live upon mush & such slops. We have as fine been and veal here as I have ever seen — beef at 8 cents & veal 5. Papa had a present of two codfish & we had some for dinner on Friday. I eat a piece as big as a half dollar buried in eggs, mashed potatoes, mustard & drawn butter, which disguised the fish entirely. Shad have been here upon the Delaware.
I broke off to take a walk from which we have just returned. One o’clock & as dinner is ready, I must defer my conclusion till afternoon.
After dinner. We came home in a tremendous storm of wind & snow. I did violence to my palate by drinking water at dinner, and console myself with some delightful pickled onions. You do not tell me what you think the swellings are that trouble Papa. D. B. ordered him to take manganese & camphor water with two drops of nitric acid in a tablespoonful 3 times a day.
Many women have died after having several children in their confinements. Mrs. Capt. Sands, for instance, with her 4th [child] & I do not know why, but I feel so fully persuaded that it will be my fate that I cannot bear to make any preparations for the future. I expect to go to town Thursday unless something prevents me so that you may direct to the care of Dawson Lee, as heretofore. I could not voluntarily separate myself from you at the time when I should most feel your absence. I will see if I can get Mrs. Norton, or some other as you prefer a Philadelphian. I have not been to Uncle’s yet. Charley Duval paid me a visit yesterday.
Do you know anything of the new Secretary ² whose nomination I see as confirmed by the Senate? Unless my letter gets to the [post] office before 3½ you will be a day later getting it, as the mail leaves here too late in the morning for the N.Y. morning mail. So my good man Willie, I shall have to say adieu. Mamma desires to be remembered to you. The rest of the family are scattered. I believe they would like me to stay here all the time, but as I cannot look for a nurse, I shall have to go to town. Adieu, dear husband.
Truly thine, — Mary
¹ Dr. William Paul Crillon Barton served as the first Chief of the Bureau of Medicine & Surgery of the Navy Medical Department from 1842 to 1844. Dr. Barton’s many accomplishments as Chief include advocating increased sick bay spaces aboard ship, proposing higher physical standards for naval recruits, and standardizing medical supplies and equipment. Barton is considered one the pioneers of naval hospital administration. Dr. Barton was succeeded by Thomas Harris.
² Mary is referring to the new Secretary of the Navy, John Young Mason, who was confirmed by the Senate following the tragic death of Secretary Thomas Gilmer on 28 February 1844 in the explosion of one of the long guns aboard the USS Princeton. President John Tyler narrowly missed being killed in the same disaster.