Despite her female gender, the critics acclaimed: "We have not for a long time heard a lady play the violin with such spirit and energy".

[5] She was decorated by Queen Victoria, and performed throughout Europe and the United States with leading orchestras including the London Philharmonic and the Boston Symphony.

[7] In 1893, Joseph Joaquim had the opportunity to listen to Jackson during a visit to the United States; he later took her on as a student at the Royal Academy of Music in Berlin.

[8] In 1898, Jackson won the Mendelssohn Scholarship, awarded by the Leipzig Conservatory in support of foreign students, receiving a prize worth approximately $90,000 in today's[when?]

[9] This funding along with the help of her patrons, including First Lady Frances Folsom Cleveland and industrialist George Vanderbilt, allowed her to study in Chicago, Paris, and Berlin.

From the proofs both musical and technical which the young lady offered […] she is sure of a career.’[11] In 1898, Jackson's London debut was another great success.

[4] On July 17, 1899, Leonora performed before Queen Victoria and the Royal Family at Windsor Castle as a part of a tour of England.

[4] Leonora took a year-long sabbatical in 1911, living on a farm in Albany, New York as she grew weary from the constant pressures of touring.

[8] In October 1915, Leonora Jackson married Dr. William Duncan McKim, a Eugenics advocate and author of "Heredity and Human Progress" 1900,[12] and a member of a prominent Baltimore merchant family.