John Alexander Dowie was a clergyman and faith healer in the United States. His claims activities came to the attention of Mirza Ghulam Ahmad after a plan to advertise himself in Europe and America and and challenge foreign Messiah claimants. This plan was brought about because of the ban on death prophecies that he was forced to sign by a British court.
Mirza Ghulam Ahmad stipulated a bunch of conditions and asked Dowie to accept his challenge within 7 months of 23 August, 1903. If Dowie did not accept the challenge during the time, the challenger would be automatically victorious; if Dowie accepted the challenge, he would die within the lifetime of the challenger.
Dowie never formally accepted the challenge, and he died in 1907. Mirza Ghulam Ahmad claimed fulfilment of the prophecy of his death.
In the same communication that was sent to Dowie, the death of John Hugh Smyth-Pigott was foretold, also within the challenger's lifetime, and without any conditions. Mr. Pigott died in 1927.
For a detailed analysis of the Dowie 'prophecy', please see: http://ahmedi.org/general/bashing-the-case-mirza-g-a-q-sahib-vs-pigott-alexander-dowie
A backup of some files related to Dowie, retrieved from: http://sites.google.com/site/leavesofhealing/
Full site about Dowie: http://www.johnalexanderdowie.com/
In 2012, reporter Lisa Black wrote a piece in which Zion historians are quoted as not agreeing with Ahmadiyya accounts (archived pdf attached):
The Ahmadiyya opened a mosque in Zion in 1982 and claim about 200 members. They often send tours through the Shiloh House, Dowie's historic home. They enjoy a reputation as a peaceful, generous people who are involved in Zion civic events, city Commissioner Shantal Taylor said.