The colors of red, white, and blue are the colors of the flags of both the Untied States and England.
The red cross that divides the white filed into four rectangles is the Cross of St. George, the patron saint of England.
The blue field in the upper left corner of the shield contains nine crosslets. These nine crosslets, in the shape of the letter X, create the the cross of St. Andrew, the patron saint of Scotland. The cross of St. Andrew honors the fact Samuel Seabury, first bishop of the Episcopal Church, was consecrated by bishops of the Anglican Church of Scotland. The reason for this was because once the colonies were independent of England Seabury was unable to take the Oath of Allegiance to the King, which at that time was an integral part of one’s ordination. The presence of the crosses of George and Andrew pay honor to the role of both countries in the development of the Episcopal Church.
The nine crosslets represent the nine dioceses that met in Philadelphia in 1789 to form the Protestant Episcopal Church in the United States of America (PECUSA). Today we are known as the Episcopal Church in the United States of American (ECUSA). The nine dioceses were Connecticut, New York, Maryland, Massachusetts, Pennsylvania, New Jersey, Delaware, Virginia, and South Carolina.