The acquisition of "Louisiana Territory" from France did nothing to help later pioneers to California; California was, around then, some portion of Spain. Be that as it may, Oregon was a piece of the Louisiana Territory. What's more, a great part of the way that pilgrims would take to California and Oregon was through the Louisiana Territory.
Maybe the greatest point was that the buy of the Louisiana Territory set the United States contiguous the Spanish provinces which later moved toward becoming Mexico. In 1835, the Texan war of autonomy from Mexico started, coming full circle in the 1836 thrashing of the Mexican powers at the Battle of San Jacinto. The acknowledgment of the Republic of Texas into the United States incited the Mexican-American War in 1845. The 1846 Bear Flag Rebellion made the fleeting California Republic, and the US smashed the Mexican powers and attached California.