Gilmore v. Gilmore
Supreme Court of California
287 P.2d 769 (1955)
During a six-year marriage, Mr. Gilmore (defendant) worked only part-time at three car dealerships he partially owned, often taking long vacations, while still drawing a substantial salary, and his ownership interest's value grew from $182,010.46 to $786,045.52 -- an increase the evidence showed was driven by a booming automobile market rather than by any particular effort or skill on his part. The trial court found his salary was community income but that the increase in his ownership interest's value was his separate property, and Mrs. Gilmore (plaintiff) appealed that separate-property characterization.
Whether the entire increase in value of a spouse's separately owned, actively managed business is the spouse's separate property when the increase is attributable to capital investment and market conditions rather than the spouse's personal efforts.