This article explains how a cause for canonization proceeds in general. Then the cause for the canonization of Frederic Ozanam, introduced in 1925, is described in detail. This cause was complicated by the fact that it was initiated long after Ozanam’s death; there was only one eyewitness who could testify about him. Nonetheless, the cause proceeded until 1962. At that point, it was decided that more work needed to be done before his heroic virtues could be properly assessed. This work, which is explained, was not done until the 1970s. The decree of Ozanam’s heroic virtues was issued in 1992. The miraculous cure attributed to him was accepted in 1995. At the time this article was written, Ozanam had not yet been officially beatified, but the way for that status had been made clear.
Sheldon, William W. C.M.
"Canonization of Frederick Ozanam: History of the Cause,"
Vincentian Heritage Journal: Vol. 17
, Article 5.
Available at: https://via.library.depaul.edu/vhj/vol17/iss1/5