The first attempt at training after she passed under her uncle's care was not a happy one in the estimation of his young ward. Being obliged to go to Washington for the session of Congress, he closed his home at Lancaster and transferred his ménage to the capital, for Buchanan always set up his household gods wherever he tarried for any length of time, his housekeeper, Miss Hetty Parker, who served him in that capacity for forty years, going with him from place to place. Harriet was left in Lancaster, in the home of some venerable spinsters of her uncle's acquaintance, who had pronounced ideas on the moral gait to be maintained by the rising generation. From her own accounts, given in letters to her uncle, she seems to have been frequently disciplined by means of her healthy young appetite. There were melodramatic occasions when she went without sugar in her tea, and was compelled to practise various similar mortifications of the flesh for which no small girl has a natural bent. After she was removed from these uncongenial surroundings she lived for some time in dread of an adverse circumstance that might return her to them. Her uncle, on whom neither the pathos nor the humor of the situation was lost, more than once suggested quizzically in his letters to her that she might like to go back to the old ladies.

When they were separated he wrote to her every day, at first from conscientious motives of the duty he owed to her, and later because of the pleasure he derived from this frequent interchange of thought and sympathy. When she was twelve years old he sent her with her sister, Mary, to boarding-school at Charlestown, West Virginia.

"Had Mary written to me that you were a good girl and had behaved yourself entirely well, I should have visited you during the Christmas holidays," he said, in the course of a letter written to her shortly after her initiation into boarding-school life.

In 1845 Buchanan became Secretary of State under President Polk. "My labors are great," he wrote to Harriet, shortly after entering upon the duties of his new office, "but they do not 'way' me down, as you write the word. Now I would say 'weigh,' but doctors may differ on this point." Further on in the same letter he continues thus: "Your friends, Mrs. Bancroft [wife of the Secretary of War] and the Pleasantons often inquire for you. They have given you somewhat of a name here, and Mrs. Polk and Miss Rucker, her niece, have several times urged me to permit you to come and pass some time with them. I have been as deaf as the adder to their request, knowing, to use a word of your grandmother, that you are too 'outsetting' already. There is a time for all things under the sun, as the wise man says, and your time will yet come." Again, he sends love from Miss Hetty, his housekeeper, and a message to the effect that she would be glad to see Harriet in Washington. "I fear she might be twice glad," added Buchanan, "once on your arrival and still more so on your departure."

It was Buchanan's custom to spend his summers or a portion of them at Bedford Springs, taking his nieces with him. To the younger it has ever been a place of happy memories. There, when she was still quite a young girl, she met the man, then also full of all the enthusiasm of youth, to whom, after exacting a prolonged devotion, she finally surrendered herself.

In one of her uncle's letters written to her in the summer of 1846 he tells her he will not be able to go to Bedford before the 10th of August, "when the season will be over and it will be too late for Mary to enact the character of belle; and you," he continued, "are quite too young to make the attempt."

He placed her, the autumn of that year, in the Visitation Convent, in Georgetown, whence she was graduated three years later with much distinction. She passed one Sunday in every month during these three years at her uncle's home on F Street, there catching her first glimpse of that world of which she was later to form a part. Her uncle was still Secretary of State, and his home was frequented by the most illustrious men who made up the public life of that day. There Harriet, looking upon herself as a full-fledged young lady, spent the first winter after her liberation from school duties. The following year, however, she passed quietly among her relatives in Pennsylvania, which was more in accord with her uncle's wishes, for she was still very young. The decision to do so was entirely voluntary on her part, which pleased Buchanan greatly, for he realized fully what a fascination the gay life of the capital held for a young girl in her high social position. He wrote her a letter full of praise for controlling what he knew to be her inclination and remaining at home. "This act of self-restraint has raised you in my estimation," he wrote, and then went on to relate frankly how gay the city was, and concluded by assuring her that Mr. John Sullivan, an Irish gentleman famous for his dinners, would be inconsolable when he learned that she was not to be there that winter.

It is supposed that no American woman ever had more offers of marriage than Harriet Lane, and it is evident, from a letter written her by her uncle about this time, that suitors had already begun to present themselves. "I wish now to give you a caution," he wrote: "never allow your affections to become interested, or engage yourself to any person, without my previous advice. You ought never to marry any person who is not able to afford you a decent and immediate support. In my experience I have witnessed the long years of patient misery and dependence which fine women have endured from rushing precipitately into matrimonial connections without sufficient reflection. Look ahead and consider the future, and act wisely in this particular."

With the incoming of Taylor's administration Buchanan retired to Wheatland, spending the ensuing four years there with occasional sallies to Washington and his summers as usual at Bedford Springs.

Harriet Lane was already a belle of far more than local repute when in 1852, her uncle having been appointed minister to England, she accompanied him thither.