This postcard appears to contain Theodore Roosevelt in Rough Rider uniform, complete with sword, at far right with his niece, Eleanor, standing next to him. I haven’t been able to identify the others in the photo, despite looking at hundreds of Roosevelt family photos online. Eleanor was born in 1884 and Theodore was inaugurated Vice President in March 1901. It’s less likely he would have appeared in uniform after that. My guess for the year of this gathering would be 1900.