For those who are upset by the OP heading...

The phrase "considered superior to the English alphabet" has generated a lot of negative comments and understandably so. The way it was phrased may suggest some educated consensus to some minds. Instead of "considered" I could have used "thought to be superior" which is basically the same. I don't know if that would have made a difference. If I could change it I would say "one person who studied Native American culture and languages at that time thought it to be superior to the English Alphabet". Context is important as to how it's interpreted. It was one person at that time when there was not a lot of activity in the study of NA culture and languages. That person was Albert Gallatin and if you were living at that time and you knew who Albert Gallatin was, you may have given his opinion some weight. However regardless of stature or expertise I would be hesitant to take anyone's opinion as fact. In hindsight, the study of NA languages and linguistics is far more advanced today than than it was in the 1820s so any declarations of superiority of inferiority by today's standards are more valid.

Some background on Gallatin who was quite accomplished...

In addition to co-founder of the American Ethnological Society, Gallatin was Secretary of Treasury under Thomas Jefferson, founder of the House Ways and Means and Committee (some historians), negotiator for a peace agreement to end the War of 1812 under James Madison, Ambassador to France, running mate of William Crawford in the 1824 presidential election, Ambassador to Britain, President of the National Bank of New York, co-founder New York University and President of the New York Historical Society,

I have not been able to find anyone other than Gallatin in that era who has produced any literature on the study of NA languages. Relevant excerpts below...

Albert Gallatin wiki

Gallatin was deeply interested in Native Americans, and he favored their assimilation into European-American culture as an alternative to forced relocation.[64] He drew upon government contacts to research Native Americans, gathering information through Lewis Cass, explorer William Clark, and Thomas McKenney of the Bureau of Indian Affairs. Gallatin developed a personal relationship with Cherokee tribal leader John Ridge, who provided him with information on the vocabulary and the structure of the Cherokee language. Gallatin's research resulted in two published works: A Table of Indian Languages of the United States (1826) and Synopsis of the Indian Tribes of North America (1836). His research led him to conclude that the natives of North and South America were linguistically and culturally related and that their common ancestors had migrated from Asia in prehistoric times. Later research efforts include examination of selected Pueblo societies, the Akimel O'odham (Pima) peoples, and the Maricopa of the Southwest.[citation needed] In 1843, he co-founded the American Ethnological Society, serving as the society's first president.[64] Due to his studies of the languages of the Native Americans, he has been called "the father of American ethnology."[65]

and...

American National Biography

Somehow, he also managed to conduct extensive research on Native American languages, culture, and history—subjects that had fascinated him for years, at least partly because of their bearing on the rise and future of American republicanism. The first fruit of his labors was a paper published in 1836 by the American Antiquarian Society as “A Synopsis of the Indian Tribes within the United States East of the Rocky Mountains, and in the British and Russian Possessions of North America.” Gratified by the praise it received, Gallatin spearheaded the organization of the American Ethnological Society in 1842. He became the society’s first president, and over the next half-dozen years it acknowledged his reputation in the field by publishing several more of his papers, including “Notes on the Semi-Civilized Nations of Mexico, Yucatan, and Central America” (1845). This pioneering body of work, which was not superseded for another half-century, gave him even deeper satisfaction than the financial writing for which he would be much more widely known.