Dear Robert and Ella

We Americans are a nation of immigrants, from the earliest Europeans to the most recent Asians. How do people keep track of their roots? Mother and I were sorting the family pictures, identifying as many as we could. It was a wearisome task. They belonged not only to another generation but to another land. Why didn't people label pictures? We didn't know who anyone was.

True, we'd maintained ties with our English kinfolk. Robert Brown, my grandfather, emigrated to America about 1885. He was skilled in ornamental stonework, and there was plenty of work here for skilled artisans. But jobs were scarce in England; despite two trips back seeking work, he stayed in America and never returned to England after 1889. In 1891, he married Ella Scales, who was born and reared on the American prairie in Minnesota. They had five children, three of whom lived to adulthood.

Pictures, letters, and caring flowed back and forth across the ocean. His sister Kate came in 1889 ''to take care of Bob.'' She was loved ''as their own'' by his wife and children. His brother Reg wanted to emigrate, but immigration laws would not admit his handicapped daughter. Reg named a younger daughter Phyllis after Robert's eldest child.

We sorted the pictures. Who was this handsome young man in silk top hat and formal attire, his mustache modern enough for 1984? His photo made a pair with the beautiful woman wearing the feather boa in the height of 1890 fashion. Who the child dressed as a drummer boy? The young man with a flute? The people looked as stiff as the cardboard backing of their sepia photographs. We seemed to have little in common with any of them. We turned to the letters.

At first we felt self-conscious about prying into mail addressed to ''Mrs. and Mrs. Robert Brown, Madelia, Watonwan Co., Minnesota, U.S.A.'' - the date Dec. 24, 1892. Then we realized that the letters were saved for us, a part of our legacy. As we read, suddenly the people in the pictures were no longer strangers but our own dear family. Letters from home.

Here is Robert's brother Eddie, the little drummer boy. He's a young man holding an oboe when a conductor invites him and brother Fred ''to play first Oboe and Flute in the 'Messiah.' ''

Fred chides Robert that his ''description of Ella is not at all vivid'' and recommends that she have her photo taken. Several small pictures of Ella confirm that she followed Fred's advice.

And then there is the letter from Steve, and we discover what special love must have sent the paired pictures of the woman in feather boa and man in top hat. For they are wedding pictures.

Steve wrote in 1893 to the sister-in-law he'd never met, ''I am engaged to a young lady who loves me, but!'' Her married friends advise her that married life is ''a store of trouble.'' He believes Ella is ''truly happy married'' and asks her to write to his sweetheart, ''and I am willing to let my happiness for the future rest on the result.''

We look with new eyes at the pictures and recall Robert Frost's lines:

And dreaming, as it were, held brotherly speech With one whose thought I had not hoped to reach.''