Reconstruct the chain with whatever contemporaneous records exist: corporate share registers, tax filings, the estate's documents and the later sale. Where a step was informal, obtain sworn statements from the estate's lawyer or accountant and the corroborating records around it.
Rebuild the chain link by link
USCIS wants to see that the investor lawfully acquired the money and how it moved to the investment. Start at the earliest point that can be documented: the company's incorporation and share register showing the father as owner, the share transfer or estate distribution to the daughter, the probate or estate accounting, the business sale agreement, the closing statement, the tax returns reporting the sale and the bank statements showing the proceeds arriving and remaining. Where the transfer to the daughter was informal, gather the accountant's working papers, the corporate resolutions if any were later prepared, the tax filings that treated her as owner and a statement from the professional involved explaining what happened and when. The file should tell the story in a short narrative, with each document cited. Presenting the bank balance alone with a statement that it was inherited is the version that draws a request for evidence.
Hypothetical example: an investor receives proceeds from selling an inherited grain-elevator business after the estate used a family trust to make distributions. The first review should begin with the decedent’s ownership, then trace the trust accounting, distribution, sale and taxes into the investment account. Trust documents, estate records, closing papers and bank statements settle the path. Build a numbered timeline before filing, and explain any transfer between accounts in real time; asking a relative to reconstruct years of transactions after a request for evidence is slower and less reliable.