| 1950's |
Clergymen from the Malankara Orthodox Church from to the United States on student visas for high education
and training. |
| 1960 |
His Grace Mathews Mar Athanasius appointed as Metropolitan of the "Outside Kerala" Diocese. |
| July 1962 |
Services are conducted by Fr. K. M. Simon in apartments in Manhattan, NY. |
| August 1962 |
Monthly Services conducted by Rev. Fr. K. M. Simon at Philadelphia, PA. |
| 1963 |
His Grace Mathews Mar Coorilos studies at General Theological Seminary in New York and celebrates occasional liturgies. |
| 1965 |
U.S. Immigration and Nationality Act Passed. |
| September 1965 |
Worship Services are occasionally conducted by Rev. Fr. K. C. Thomas in Washington, D.C. |
| 1968 |
Services are conducted at Union Theological Seminary under the leadership of Very Rev. Dr. K. M. Simon. |
| January 15, 1972 |
First Malankara Orthodox Syrian Parish in the United States, St. Thomas, Manhattan, incorporated under the state of New York. |
| November 1972 |
Congregation forms in the Bronx, New York |
| 1972 |
St. Mary's, Boston recognized as an official parish under the leadership of Rev. Fr. K. C. George. |
| 1973 |
Congregation started in Dallas, Texas. |
| 1974 |
Congregation started in Houston, Texas. |
| October 27, 1975 |
Mar Athanasius elevated to Catholicos of the East & Malankara Metropolitan. |
| 1975 |
Fr. K. C. Thomas is consecrated Metropolitan and given the name Mar Makarios. |
| March 4, 1975 |
St. Thomas, Houston, Texas recognized as an official parish under the leadership of Rev. Fr. C. O. Vargis, Vicar. |
| 1975 |
Congregation started in Los Angeles, California |
| 1975 |
New York/New Jersey divided into five regions, Manhattan, Queens, Staten Island, Brooklyn and New Jersey. |
| March 22, 1976 |
Diocese shuffle: American parishes now under the Bombay Diocese. |
| 1976 |
St. Thomas Indian Orthodox Church recognized as first official parish in Philadelphia, under the leadership of Rev. Fr. K. Mathai, Vicar. |
| 1978 |
"American Diocese" Forms. |
| April 1978 |
St. Gregorios Orthodox Church in Illinois formed. |
| July 14, 1979 |
Enthronement of His Grace Dr. Thomas Mar Makarios as Diocesan Metropolitan. |
| 1992 |
His Grace Mathews Mar Barnabas appointed as the Assistant to the His Holiness the Catholicos, Mathews II, who was in charge of the American Diocese. |
| March 1993 |
Enthronement of His Grace Mathews Mar Barnabas as the Diocesan Metropolitan |
| 2002 |
His Grace Zachariah Mar Nicholovos appointed as the Assistant Metropolitan of the American Diocese. |
| March 2009 |
The American Diocese is divided into the Northeast American Diocese and the Southwest American Diocese |
| June 13, 2009 |
The Diocese of South-West America is inaugurated. |