His father, Alexander Nelson Webb, was a leading journalist of his day and perhaps influenced his son’s later journalistic exploits.
Webb received his early education at the Home School in Glendale, Massachusetts and later attended Claverack College, an advanced high school near Hudson, New York. He became editor of the Unionville Republican, Unionville, Missouri. His prowess as a journalist was soon apparent, and he was offered the city editorship of the St. Joseph Gazette in St. Joseph, Missouri. Next he became associate editor of the Missouri Morning Journal. Later he became the Assistant City Editor of the Missouri Republican in St. Louis. This newspaper was the second oldest and largest daily newspaper at that time.
While working for the Missouri Republican, he was appointed (in September, 1887) by President Cleveland to be Consular Representative to the Philippines at the U.S. office at Manila. According to the editor of his book The Three Lectures, he had given up any concept of religion at least fifteen years before that point.
In 1887 Webb was introduced to Islam by the works of Mirza Ghulam Ahmad of Qadian, India, the founder of the Ahmadiyya movement. Webb wrote two letters to Ghulam Ahmad. Webb's first clear step toward Islam was expressed in these correspondences. These letters were published then in Ghulam Ahmad's book "Shahne-e-Haqq" page 372 and 439. At that time he had yet to meet a Muslim but was put in contact with several Muslims in India by a local Parsi businessman. A newspaper publisher, Budruddin Abdulla Kur of Bombay, published several of Webb's letters in his paper. A local businessman, Hajee Abdulla Arab, a follower of Ghulam Ahmad, saw these letters and went to Manila to see Webb. In 1888, he formally declared himself to be a Muslim.
After the visit, Webb began plans to tour India and then return to the U.S. to propagate Islam. Webb's wife, Ella G. Webb, and their three children had also accepted Islam by this time. Hajee Abdulla returned to India and raised funds for Webb's tour. Webb visited Poona, Bombay, Calcutta, Hyderabad, and Madras and gave speeches in each town. In 1892 he travelled to Egypt and Turkey where he could continue studying Islam. While in Istanbul in 1893, he resigned his post with the State Department and returned to America.
Settling in New York, he established the Oriental Publishing Company at 1122 Upper Broadway. This company published his writings (including his magnum opus- Islam in America), such as:Islam in America – contained 70 pages divided into eight chapters:
I) Why I Became a Muslim
II) An Outline of Islamic Faith
III) The Five Pillars of Practice
IV) Islam in Its Philosophic Aspect
V) Polygamy and the Purdah
VI) Popular Errors Refuted
VII) The Muslim Defensive Wars
VIII) The American Islamic Propaganda
Along with this venture he started the organ of the American Muslim Propagation Movement called Moslem World. The first issue appeared May 12, 1893, and was dedicated to The Interests of the American Islamic Propaganda and "[t]o spread the light of Islam in America". It lasted for seven monthly issues (May to November 1893).
In December 1893, John A. Lant and Emin L. Nabakoff broke from Webb's movement and formed the First Society for the Study of Islam and set up shop in Union Square.
Webb was the main representative for Islam at the 1893 World Parliament of Religions in Chicago. On September 20 and 21, 1893, he gave two speeches. His speeches were entitled: The Influence of Social Condition and The Spirit of Islam and were published in the large two volume proceedings of the Parliament called The First World's Parliament of Religions (1894).
For the rest of his life he was the main spokesman for Islam in America. Many of America’s most prominent thinkers heard him speak on the Islamic Faith, including Mark Twain.
On Broadway, in Manhattan, he founded a short-lived masjid (Mosque). The reasons for the termination of this Masjid are unknown, but it could be due to a lack of financial support from India. Throughout the rest of America he started study circles, i.e. in Chicago, Washington, D.C., Newark, Manhattan, Kansas City, Philadelphia, Pittsburgh, and Cleveland. They were named Mecca Study Circle No. I (NYC), Koran Study Circle, Capital Study Circle No. 4, etc. Each using an Islamic city or reference in its title. It is likely they studied Webb's works and those he suggested. The last meeting was in 1943 in Manhattan and was attended by his daughter Aliyyah.
He is also known for his writing of two booklets about the Armenian Genocide from a Muslim point of view: The Armenian Troubles and Where the Responsibility Lies and A Few Facts About Turkey Under the Rule of Abdul Hamid II. He was appointed the Honorary Turkish Consul in New York by Sultan Abdul Hamid II. The Sultan had been shown plans by Webb for a Muslim cemetery and Masjid and complimented Webb on them. These plans never materialized.
From 1898 to the time of his death on October 1, 1916, aged 69, he lived in Rutherford, New Jersey. There he owned and edited the “Rutherford Times”. He was buried in Hillside Cemetery, Lyndhurst, on the outskirts of Rutherford.