Vernon Schaub has informed us that this picture is of the William and Louise Mertz Golden Wedding Anniversary in 1916. The house is the Mertz home at the corner of Ireland and Erskine streets in College Heights, Seguin, Texas. His identifications are available as a JPG as well as copied below.
The picture was previously misidentified as the Schaper-Mertz Reunion and Schaper 50th Anniversary in Seguin in 1902.

78 Attendees at Schaper Golden Wedding Anniversary c1902

Click on a person to enlarge that area. The two front rows are grand children of William and Louise Mertz.
Third row, left to right: Adolph Oeffinger, Mrs Adolph (Ellie) Oeffinger, Mrs. Oscar (Flossie) Schaper, Oscar Schaper, Edna Mertz, Mrs. William (Louisa) Mertz, William Mertz, Edna Mertz.
Fourth row, left to tight: Willie Brannies, Mrs. Willie (Mary) Brannies, Mrs. Emil (Ida) Faseler, Emil Faseler, Mrs. John (Mathilda) Hasse, Mrs. William (Elfrieda) Hannah, Albert Schraub, Mrs. Albert (Lydia) Schraub, Mrs. Edwin (Della) Mertz, Mrs.. Dan (Johanna) Schaper, Dan Schaper, Mrs. Willie (Nathalia) Willmann, Mrs. Henry (Martha) Mertz, Willie Willmann, and Henry Mertz.
Porch. People standing on the porch are friends.

Eight people in upper right Eleven people in upper center Eleven people in upper left Six people to the right of center Ten people to left of center Eight people in the center of the picture Seven children in lower right Six children in lower left Six children at bottom center