This house was built in two sections and moved to current location. There is a partial wall between the dining and living area and I would like to build a half wall using this 5' section of wall so we can have more light in the living area. Would 5' make a crucial difference in a load bearing wall, if it is a load bearing wall and I plan on installing a header and 4x4 column.
If I understand what you are saying, you would like to remove 5 feet of load bearing wall, and replace with a header and a 4x4 column. Any time you remove part of a load bearing wall, you need to have the header sized to carry the new load, similarly for the column. Sometimes you need an engineer to look at the loading and size the structural elements, in some cases the contractor does his own computations prior to pulling the permit. So in answer to your question, five feet can make a large load difference, and you need to design carefully.